New Rifle Build- Bullet and Caliber- Mono metal- Thoughts?

[DagOtto]

I agree. Yet some of his thoughts could use some modernization too.

In this Internet age, where information is no longer vetted prior to being published, I think one of the most important life skills is the ability to discern BS from informative value. There’s lots of both on this site. And sometimes, both come from the same source. I’ve learned from both schools of thought and do not fully dismiss, nor blindly subscribe, to either side.

One of things I've found most interesting in comparing the content and opinions from Form and Barsness is how much their "old school" and "new school" opinions alignt. In one of Barsness's chapters in he Gun Gack books he literally says that recoil negatively affects almost everyone's accuracy level to the point that smaller calibers are probably a more affective and humane killer of animals. Between the two of them I think there is probably more in agreement than not. I found his stuff to be mostly rooted in fact much more than most.

 

[DagOtto]

I will admit I did not read through all the pages on this but it is something I've been debating myself. Right now, by the way, I shoot a 6.5 PRC with 147 grain DRTs
They are not making the 147 grain anymore who knows if they ever will again...
I also know that all of their products are out of stock and that concerns me a bit.
I would love to make a 6 Mill creedmoor. For out to 500 it would absolutely be a wonderful caliber for killing all sized game but DRT only makes a 95 grain bullet and I'm concerned with that weight. Maybe @Formidilosus has some thoughts on that.
If we're looking at a one and done type scenario it's really tough to beat the 6.5 creedmoor IMO with the right bullet such as the 135 grain DRT if it gets back in stock anytime soon. Simply bc of the vast number of rifles and manufacturers.
Also if we are not to see much more of the DRT ammunition (which would be a true disappointment) you might look at Maker's bullets as their design seems to expand significantly even for the standard mushroom bullet type, with a larger expansion character vs similar style of monolithic bullets.
Cheers and good luck!

Hey MatukaJoe,

Form did weigh in on this discussion (probably on page 2) and says that between .223, 6mm, 6.5mm, 7mm and .308 the same model of bullet will create wound channels that are almost indistinguishable from small to large calibers even though the weight and size of the bullets are so different. (this is a pretty massive paraphrase.) He also said that 6mm CM is the easy choice if your looking for an easy button. And he said, if you choose to shoot non-lead your first best choice is DRT, and second (but behind quite a bit,) is Barnes LRX.

I find his claim about calibers not affecting "real world" wound channel size , along with his claim that any decently designed hunting bullet almost never fail from lack of penetration--- to be mind blowing. These two factoids alone are enough to pretty much blow-up 100 years of what we have been told by the hunting press, the gun and ammo industry, professional guides, and our good old grandpas. The really crazy thing is that his arguments about both make a lot of sense. And if he is to be believed, he has a very large sampling of dead animals to prove these claims out. Nathan Foster is about the only other ballistician / terminal ballistics guy I've heard of who has thousands and thousands of animals he's personally shot/witnessed and autopsied. Incidentally, Foster once told me that for elk he'd recommend a .30 caliber bullet. So he has differing opinions than Form, but is 100% in alignment with him on match bullets for affective wound channel creation and against traditional monos.

I was literally mid-build on a 300 WSM when I came across Form's interviews with the Exo Mtn gear guys.. and after listening to those shows two or three times each I abandoned that build (had the proof barrel already,) and built a 6.5 CM instead. In 5 days I hope to shoot an antelope or two with this build and I can't wait to put his advice to the test.

I believe that there is a set of "best practices" for affectivey and humanly killing game animals with a rifle. And I belive that facts and studies can be either found or created to prove what is BS and what is true. But the industry doesn't seem to want to invest in that kind of data. (military clearly does.) I would give my left nad to have an independent testing facililty publish gel testing of bullets impacting FBI gel at 3000, 2500, 2000 and 1500 FPS. They could even scan the gel blocks with MRI type scanning and develop a true 3d volumetric model of wound channels. How hard could it be? Problem is that it would probably hurt a lot of bullet sales. I can see why the industry would much rather have us gun dorks arguing endlessly about X and Y bullets and calibers. And besides, what would we do with ourselves?

 

[DagOtto]

How about put a custom barrel on it chambered in 30-06 only use a 24" barrel instead of the 22" factory barrel they come with. Put a nice aftermarket stock on it and have a gunsmith fine tune the trigger to 2.5 pounds. No flies on the 30-06 especially with a well bedded and tuned 24" barrel. Keep it but make it better.

Thanks for the idea. I have discovered that I shoot much better with lower recoil (and especially suppressed.) Over the last 20 years I've migrated slowly down from .338 win mag. (HATED that gun!) to the 30-06, to a .308 (still love this one,) and now down to 6.5 CM and maybe even to 6 CM. It hasn't been as straight lined as that really, as I've got a .280 AI, a couple of .243s etc. But the bottom line is that less recoil has allowed me to shoot better, and I've shot a LOT more practice too.

The other reason i'm shying away from the good ole 30-06 is that I'm shooting non-lead ammo and the traditional mono-metal bullets (Barnes, Federal Trophy Copper, Nosler E-Tip, Hornady CX) all need to impact animals at 2000 FPS or higher for affective expansion. And love the 06 and the .308 win as much as I do,, they don't give me the velocity I need to hunt much past 300 yards.

 

[AZ_Hunter]

Thanks, I have been using Nosler's reloading data to come up with my capacity and speeds. I've taken the average "max" of the various powders tried and then deducted 50 fps per inch from the test barrel listed to get to approximate 18" barrel speeds. Not super accurate, but I feel that the comparison between cartridges is probably pretty realistic.

50fps per inch is way too much. 25 is more realistic, and sometimes not even that much.

 

[MatukaJoe]

Hey MatukaJoe,

Form did weigh in on this discussion (probably on page 2) and says that between .223, 6mm, 6.5mm, 7mm and .308 the same model of bullet will create wound channels that are almost indistinguishable from small to large calibers even though the weight and size of the bullets are so different. (this is a pretty massive paraphrase.) He also said that 6mm CM is the easy choice if your looking for an easy button. And he said, if you choose to shoot non-lead your first best choice is DRT, and second (but behind quite a bit,) is Barnes LRX.

I find his claim about calibers not affecting "real world" wound channel size , along with his claim that any decently designed hunting bullet almost never fail from lack of penetration--- to be mind blowing. These two factoids alone are enough to pretty much blow-up 100 years of what we have been told by the hunting press, the gun and ammo industry, professional guides, and our good old grandpas. The really crazy thing is that his arguments about both make a lot of sense. And if he is to be believed, he has a very large sampling of dead animals to prove these claims out. Nathan Foster is about the only other ballistician / terminal ballistics guy I've heard of who has thousands and thousands of animals he's personally shot/witnessed and autopsied. Incidentally, Foster once told me that for elk he'd recommend a .30 caliber bullet. So he has differing opinions than Form, but is 100% in alignment with him on match bullets for affective wound channel creation and against traditional monos.

I was literally mid-build on a 300 WSM when I came across Form's interviews with the Exo Mtn gear guys.. and after listening to those shows two or three times each I abandoned that build (had the proof barrel already,) and built a 6.5 CM instead. In 5 days I hope to shoot an antelope or two with this build and I can't wait to put his advice to the test.

I believe that there is a set of "best practices" for affectivey and humanly killing game animals with a rifle. And I belive that facts and studies can be either found or created to prove what is BS and what is true. But the industry doesn't seem to want to invest in that kind of data. (military clearly does.) I would give my left nad to have an independent testing facililty publish gel testing of bullets impacting FBI gel at 3000, 2500, 2000 and 1500 FPS. They could even scan the gel blocks with MRI type scanning and develop a true 3d volumetric model of wound channels. How hard could it be? Problem is that it would probably hurt a lot of bullet sales. I can see why the industry would much rather have us gun dorks arguing endlessly about X and Y bullets and calibers. And besides, what would we do with ourselves?

FWIW I don't know Form although I do know Mark and Steve through both owning an EXO but also via NW Sportsman's Show. I went down the smaller is better rabbit hole well over a year ago. before I heard Form and before the Experience Podcast highlighted this as well. Although I am glad they are making note of all such. My own anecdotal evidence seemed to show that to me previously. Discussing this further with people who work in industry (who I won't name bc I don't want to misquote nor ever say so and so says so ergo it must be right) looking at wound channels, how energy doesn't matter, reading FBI papers (yeah I am one of those geeks I did that before Form even mentioned) it just made no sense to me that a bullet lets just say doubled in size *especially if bonded or monolithic* could make any significant wounding difference between .612 vs .568 vs .528; further, that a bullet which lost no mass or extremely little could somehow impart more wounding and be a more efficient method of wounding and killing. I then found DRT bullets and was excited by how they performed terminally. I prefer nonlead mostly because of the optic to non-hunting public as well as because I prefer not to put lead into other critters that will eat any offal and leftover carcass matter I may leave in the field.
Because of my speaking with others, and my own experiences, I bought a 6.5 PRC barreled action and put it in a Stocky's VG2 stock (this was before the Rokstok made its appearance). My whole goal was a rifle that carried factory-loaded ammo at speeds of 2200 fps to 500 yards or more but that had lesser recoil and was set up in a way that was most comfortable for me to shoot plus at what I considered an overall affordable cost. That way depending on bullet construction I felt I would have a 600-yard rifle without issue/fail. I have been very happy with my experiences with the rifle. My only regret is I wish I had started with the 6mm CM hah! I know Form has discussed different caliber sizes with terminal results but I am still curious about bullet grains with the push to use "heavy for caliber." What is considered too light or is there such a thing *depending on velocity levels at 500 yards in this plan/case study*?
Unfortunately, I also agree manufacturers have no impetus to run such tests or even if they have to publish such data. It's too challenging to inform the general public's mind or too costly to detail the information in a digestible manner for all.
Oh and as a side note for less or nonlead I tried the Hornady CX and my rifle did not like them. It loved the Federal Terminal Ascent which I used for a while before switching to DRT. There was a semi custom load company that was factory loading the DRT 147s while they were still around and it is a real kick to the crotch knowing they are not anymore.
Great topic IMO btw.

 

[Formidilosus]

I know Form has discussed different caliber sizes with terminal results but I am still curious about bullet grains with the push to use "heavy for caliber." What is considered too light or is there such a thing *depending on velocity levels at 500 yards in this plan/case study*?

In general, “heavy for caliber” starts at about:

.224- 75gr
.243- 105-110gr
.257- 125gr
.264- 140gr
.277- 160gr
.284- 170gr
.308- 200gr
.338- 270gr


Those are general numbers, and could be argued either side a bit.

Unfortunately, I also agree manufacturers have no impetus to run such tests or even if they have to publish such data. It's too challenging to inform the general public's mind or too costly to detail the information in a digestible manner for all.

Actually, they are encouraged not to. Look at what Hornady has done, S2H, etc. When you remove lore and myth and use data, you alienate a portion of the population. People really don’t like having their beliefs and feelings challenged.

 

[Jason Snyder]

No

A custom 6mm-06 build on the the Tikka action would be pretty sweet and would scream out of a 24" barrel.

Not to hi jack the thread, but other than slightly less recoil I’m trying to determine how much, if any advantage there is to building a 6-06 vs spinning a fast twist 25-06 barrel on.

Hammer load data shows 3200 fps for a 120 HHT in a 25-06.

 

[Macintosh]

In general, “heavy for caliber” starts at about:

.224- 75gr
.243- 105-110gr
.257- 125gr
.264- 140gr
.277- 160gr
.284- 170gr
.308- 200gr
.338- 270gr


Those are general numbers, and could be argued either side a bit.

I am not @MatukaJoe and dont want to speak for him, but I interpreted his statement or questions as “Im curious about what you recommend as “ideal” for bullet weight in general when speaking only about monos, given the somewhat ubiquitous push for heavy for caliber lead bullets”…in other words, not what weight constitutes a heavy for caliber bullet in a given caliber, but what do you see as the best course in general for hunters using mono bullets AND wishing to maximize effective terminal range and minimize recoil. Is that still good advice across the board when speaking specifically about monos?

I think I know your answer from other threads (I think its in this thread as well), but curious on the question around the common advice to “go heavy for caliber at longer range”, especially if its different for some of the newer fragmenting monos as opposed to traditional ones.

 

[MatukaJoe]

In general, “heavy for caliber” starts at about:

.224- 75gr
.243- 105-110gr
.257- 125gr
.264- 140gr
.277- 160gr
.284- 170gr
.308- 200gr
.338- 270gr


Those are general numbers, and could be argued either side a bit.





Actually, they are encouraged not to. Look at what Hornady has done, S2H, etc. When you remove lore and myth and use data, you alienate a portion of the population. People really don’t like having their beliefs and feelings challenged.

Thanks @Formidilosus and @Macintosh you both were helpful. I guess where I am still getting some paralysis by analysis is that if the DRT ammo continues to limit their .243 bullets to 95 grain is this a serious issue in using such out of a 6CM? Especially to a rifle build with the intent to take game to 500 yards. I have zero concerns about caliber size but find myself hanging up on bullet weight. Thanks for all the input from you both and I agree Form people don't like it when their beliefs are challenged even worse if you can show with proof they are missing data or simply wrong.
Also sorry for hijacking the OPs thread with this rabbit hole! Hopefull its helpful to them as well!

 

[MatukaJoe]

In hindsight I think are better way to ask this @Formidilosus ...
If a bullet can achieve maximum expansion is it ever too light to have enough penetration to the vitals or if by nature of being at maximum expansion is the speed enough?
Could a 95 grain 243 bullet using the above example have maximum expansion but fail to reach penetration depth to vitals on an elk or a deer?

 

[Formidilosus]

@Macintosh and @MatukaJoe

I misunderstood. Specifically about monos and weight- look at each bullet individually as far as what it needs for full upset/exoansion (vice a slight nose peel), the real muzzle velocity it will achieve, and it’s legitimate BC. Then see what range that is. Do that for each weight/type of bullet and pick which has the longest range. With conventional monos it usually is a mid weight bullet that wins out.

Thanks @Formidilosus and @Macintosh you both were helpful. I guess where I am still getting some paralysis by analysis is that if the DRT ammo continues to limit their .243 bullets to 95 grain is this a serious issue in using such out of a 6CM? Especially to a rifle build with the intent to take game to 500 yards. I have zero concerns about caliber size but find myself hanging up on bullet weight. Thanks for all the input from you both and I agree Form people don't like it when their beliefs are challenged even worse if you can show with proof they are missing data or simply wrong.
Also sorry for hijacking the OPs thread with this rabbit hole! Hopefull its helpful to them as well!

With regards to the 95gr DRT, no- it being 95gr does not remove it from contention for 500 yard use. The BC isn’t great, but the 6cm’s MV is high enough to make 500 yards inside its terminal range.

 

[Formidilosus]

In hindsight I think are better way to ask this @Formidilosus ...
If a bullet can achieve maximum expansion is it ever too light to have enough penetration to the vitals or if by nature of being at maximum expansion is the speed enough?
Could a 95 grain 243 bullet using the above example have maximum expansion but fail to reach penetration depth to vitals on an elk or a deer?

That is based on bullet construction, not weight. A 65gr .243 bullet could be made to penetrate 30 inches. And, the lower the impact velocity the less upset/expansion and the deeper the penetration for functional use.

The construction of the 95gr DRT and 95gr Barnes LRX are both sufficient to penetrate deep enough for big game. The DRT will create larger wounds on average.

 

[MatukaJoe]

That is based on bullet contraction, not weight. A 65gr .243 bullet could be made to penetrate 30 inches. And, the lower the impact velocity the less upset/expansion, and the deeper the penetration for functional use.

The construction of the 95gr DRT and 95gr Barnes LRX are both sufficient to penetrate deep enough for big game. The DRT will create larger wounds in average.

Thanks again to you both!

 

[DagOtto]

Also sorry for hijacking the OPs thread with this rabbit hole! Hopefull its helpful to them as well!

No apologies required- I am very focused on these same questions and glad that there are others a to share this conversation with.

 

[DagOtto]

Thanks again to you both!

Okay, based on all this data and discussion Im going to order an 18” 6cm barrel with the intent of loading 95 grain DRTs and hopefully having a very low recoil hunting rifle for every game animal in Montana and for lots of practical positional practice at the range.

in reply to an earlier posters question - if I did not already have a absolute tack-driver in 6.5 CM I would more than likely be building this one as a 6.5-06.

 

[JohnB]

Apologies if I've missed this but is there a consensus on a minimum velocity for DRT bullets? I'm particularly interested in the 117 gr 270 bullets.

 

[DagOtto]

Okay, based on all this data and discussion Im going to order an 18” 6cm barrel with the intent of loading 95 grain DRTs and hopefully having a very low recoil hunting rifle for every game animal in Montana and for lots of practical positional practice at the range.

in reply to an earlier posters question - if I did not already have a absolute tack-driver in 6.5 CM I would more than likely be building this one as a 6.5-06.

Before I finalize barrel order I’d love advice on barrel details. I’ve only used proof carbon for builds up to this point so I’m a newb when it comes to all of these options:

1-Twist rate— keeping in mind I’m looking to build the most accurate 6cm system for 600 yard max, mono metals (which means lighter than the rockslide standard) 95-100 grain bullets. I’m thinking a 1:8 twist is best choice. When I plug the numbers into Bergers twist rate calculator this seems to work.. am I missing anything important?

Profile- I will be using a light suppressor for hunting (banish bc) and am trying to build a 8.5 pound gun (with scope and suppressor.) the helpful folks at x-caliber say the barrel needs .750 minimum dia.to thread the 5/8x24 and suggest number 20 Sendero profile. (3.75 pound estimate for 18” barrel.) I am wondering if there are ways to get a lighter thinner profile while still maintaining the required contact area and dia for threading 5/8x24? I remember seeing someone on Rokslide say they use some kind of adapter that makes the end of a skinny barrel accept the suppressor. ??

3- 6 groove, 3 groove or 3r groove ??

Thanks

 

[Formidilosus]

Before I finalize barrel order I’d love advice on barrel details. I’ve only used proof carbon for builds up to this point so I’m a newb when it comes to all of these options:

1-Twist rate— keeping in mind I’m looking to build the most accurate 6cm system for 600 yard max, mono metals (which means lighter than the rockslide standard) 95-100 grain bullets. I’m thinking a 1:8 twist is best choice. When I plug the numbers into Bergers twist rate calculator this seems to work.. am I missing anything important?

If you have the option, 1-7.5” twist is the huckleberry. That way if for some reason the DRT’s don’t work for that barrel, you have the other better bullet options.

Profile- I will be using a light suppressor for hunting (banish bc) and am trying to build a 8.5 pound gun (with scope and suppressor.) the helpful folks at x-caliber say the barrel needs .750 minimum dia.to thread the 5/8x24 and suggest number 20 Sendero profile. (3.75 pound estimate for 18” barrel.) I am wondering if there are ways to get a lighter thinner profile while still maintaining the required contact area and dia for threading 5/8x24? I remember seeing someone on Rokslide say they use some kind of adapter that makes the end of a skinny barrel accept the suppressor. ??

Well first, don’t use a carbon barrel. Second, get a T3 lite profile dupe with either the flare at the end for 5/8x24 or- thread 1/2x28 then use an adapter to bring it to 5-8x24. Easy.

Thats the only way you are making 8.5lbs scopes and suppressed.

3- 6 groove, 3 groove or 3r groove ??

Thanks

Ehh. Hasn’t seemed to make a difference for this use.

 

[DagOtto]

Apologies if I've missed this but is there a consensus on a minimum velocity for DRT bullets? I'm particularly interested in the 117 gr 270 bullets.

I’m using 2800 fps as the basement for impact velocity. But I am only going off of advice from other forum threads. I have not been able to find any real testing data or any velocities published by DRT.

 

[DagOtto]

If you have the option, 1-7.5” twist is the huckleberry. That way if for some reason the DRT’s don’t work for that barrel, you have the other better bullet options.




Well first, don’t use a carbon barrel. Second, get a T3 lite profile dupe with either the flare at the end for 5/8x24 or- thread 1/2x28 then use an adapter to bring it to 5-8x24. Easy.

Thats the only way you are making 8.5lbs scopes and suppressed.





Ehh. Hasn’t seemed to make a difference for this use.

Thanks much. Ordering today!