Another question on my Wifes 7mm-08

[Luked]

So my wife is a newer hunter and i got her a 7mm-08 she really likes. With her being a newer hunter she is a bit recoil sensitive.
She shoots Hornady Custom Lite low Recoil rounds that use a 120gr SST. And the rifle shoots them well

So I am following Form's simple reloading technique to spin her up some rounds.
What I noticed was the manual has COAL as 2.700 the factory rounds are 2.800 COAL.

Do you guys think that this longer round is the way they are getting the "Low Recoil" for these rounds?
I picked a Mid gr charge of 40gr of Varget for her reloads. But didn't notice the longer length with the factory rounds.
I know in the thread Form has he shows that COAL lengths don't really matter that much if any on accuracy. but the recoil part is what I am looking to reduce.
@Formidilosus any ideas by chance?

 

[Grassymike]

Pretty sure overall length will make absolutely no difference to recoil. On the other hand heavier bullets or higher powder charges will. Every time you increase powder charges equals more energy and more recoil. For what you are trying to do stick with starting loads from a reloading manual and use light for caliber bullets. The 120 grain bullets from your factory load would be a great place to start.

 

[KenLee]

If you decide to step up speed with a 120gr bullet, the factory 7mm-08 NBT are wicked little pills. Thicker jacket per bullet weight than most NBT. Recoil isn't too much more than factory lite recoil.

 

[Alwaysworking]

I would guess the shorter coal is to reduce the volume of the space the power charge occupies. They would be using a light charge of fast burning power as charge weight contributes significantly to recoil

 

[seand]

Right on, awesome you are considering reduced recoil. Book min loads or reduced loads with H4895.

Reduced Rifle Loads | Handloader Magazine

www.handloadermagazine.com

You can also add a silencer to help even more. But she will shoot a .223 even better.

 

[Vern400]

If it shoots good at 2.80 why not load it at 2.80?
The mag will probably handle 2.82 or better. That's one best thing that you did different from what shot good.

 

[gobblinglawyer]

When my son was 9, I loaded him up a reduced recoil load of 38 grains of Varget with a 140 grain Nosler BT. Deadly medicine on whitetail deer in GA. He probably killed a dozen with that load.

 

[Luked]

If it shoots good at 2.80 why not load it at 2.80?
The mag will probably handle 2.82 or better. That's one best thing that you did different from what shot good.

Will give the 2.800 a try next.
Didnt realize they were that long until I already had 10 loaded at 2.700

 

[A382DWDZQ]

Just want to check something here @Luked. I don’t see a .284 120gr SST in the Hornady app. The two projectiles they have are not the SST. If that is where you’re finding that book measurement of 2.700, then I’m guessing it is for a different projectile than the SST. The load data for those other two might be interchangeable, but not the COAL. I’d use 2.80 for the SST.

Nosler for the 120 BT is 2.80, and so is Barnes 120TTSX. I’d use their load data if you do have SSTs. If you are seating deeper, you’re getting higher pressure.

For reduced recoil, pick up a copy of the Lee manual and you can come up with some good reduced loads. They have a section for it and a formula to use with different powder and bullet combos. Both H4895 and IMR4895 are good for up to 40% reduced from max. The H4198 and IMR4198 are also reliable reduced, and 3031. That’s if a starting book load is too stiff.

 

[SloppyJ]

As you increase the seating depth, the pressure will rise so I'd venture to say that there is some impact.

If it's shooting well then you're good to go, I wouldn't sweat the seating depth. But run a seating depth test for yourself to see if you think it matters or not for accuracy. First step would be to find the lands with that bullet and measure to the ogive and not the tip of the bullet. Too much variation in bullet overall length to be consistent.

 

[Pharmseller]

As you increase the seating depth, the pressure will rise so I'd venture to say that there is some impact.

In my experience velocity (therefore pressure) is highest at the extremes - close to the lands, and close to compressed. Think of it as a normal distribution curve, with higher velocity at the tails. In the middle of the curve the velocity drops.





P

 

[Luked]

Just want to check something here @Luked. I don’t see a .284 120gr SST in the Hornady app. The two projectiles they have are not the SST. If that is where you’re finding that book measurement of 2.700, then I’m guessing it is for a different projectile than the SST. The load data for those other two might be interchangeable, but not the COAL. I’d use 2.80 for the SST.

Nosler for the 120 BT is 2.80, and so is Barnes 120TTSX. I’d use their load data if you do have SSTs. If you are seating deeper, you’re getting higher pressure.

For reduced recoil, pick up a copy of the Lee manual and you can come up with some good reduced loads. They have a section for it and a formula to use with different powder and bullet combos. Both H4895 and IMR4895 are good for up to 40% reduced from max. The H4198 and IMR4198 are also reliable reduced, and 3031. That’s if a starting book load is too stiff.

You are correct. Sorry
I just checked my manual and it is showing a 120gr V-Max not an SST.

 

[SloppyJ]

In my experience velocity (therefore pressure) is highest at the extremes - close to the lands, and close to compressed. Think of it as a normal distribution curve, with higher velocity at the tails. In the middle of the curve the velocity drops.





P

Not disagreeing with you at all. I don't know how far 2.8 is off his lands but if he's not touching I'd be willing to bet that seating the bullet deeper will result in increased pressure. I'm only basing that off of me playing around in quickload. Regardless, if it's not jammed into the lands or compressing the charge, the impact is arbitrary.

 

[A382DWDZQ]

You are correct. Sorry
I just checked my manual and it is showing a 120gr V-Max not an SST.

I'm still curious how you got 120gr .284 SSTs. I don't see them as an option anywhere. Did you get them as pulls?

On the reduced loads, it looks like the MV on the Hornady ammo is 2,676.
IMR 3031 would be my top choice for replicating it. High burn rate, high velocity compared to PSI, and pretty high case fill. ~36gr would be pretty close with a 24" barrel, and about 2,600 with a 20" barrel.
That recoil would come in somewhere between a 7.62x39 and a 243, ~10-11ftlbs. That'll be above 1800fps out to 350yds.

 

[Luked]

I'm still curious how you got 120gr .284 SSTs. I don't see them as an option anywhere. Did you get them as pulls?

Had that wrong as well. What I have is 120gr V-Max bullets.
I guess I had SST stuck in my head as that is what the factory rounds we have for her rifle are.

 

[Fmuguira]

As already mentioned; H4895 !! That’s your huckleberry and can be loaded down to 60% of the full power H4895 loads or anywhere between those two charges. I ve found 70% of max charge weight to typically give sub-moa accuracy in numerous calibers that have H4895 load data.

Google Winchester Youth Loads and you ll find the detail to this as written by z Hodgdon powder company. Remember, this is for H4895 only; not other designations of 4895.

Good luck, they re sweet loads and performance to 209-250 yards is fantastic.

 

[Fireflyfishing]

Thread barrel. Buy a suppressor or brake and use whatever ammo you want. Problem solved.

 

[A382DWDZQ]

Remember, this is for H4895 only; not other designations of 4895.

It’s for IMR4895 also.

 

[Fmuguira]

I ve never seen published data from Hodgdon, who owns IMR now, on IMR4895 reduced loads but if so then that d be another good source.

 

[A382DWDZQ]

I ve never seen published data from Hodgdon, who owns IMR now, on IMR4895 reduced loads but if so then that d be another good source.

I don't remember where I saw that mentioned now, but it seems to hold up in everything I have read about reduced loads. The Lee Modern Reloading 2nd Edition has a section devoted to reduced load development. Between the Lee book and the Lyman Cast Bullet Handbook, there is quite a lot of data out there. A couple other good sources are the M1 Garand loads in the Hornady manual and the MELs Moderate Effective Loads in, I think, the 2009 Hodgdon manual. For hunting purposes, it is probably not necessary to reduce all that much.

Using the Lee formula for 160gr bullets, it ends up like so:

Powder	%Reduced to get 2,000fps	Charge	Original Recoil	Reduced Recoil	Propellant % Burnt	Case fill
IMR4895	68%	27	7.8-9.2	16.2-17.2	73.6%	61
H4895	61%	23.5	7.3-8.67	15-16.16	70.5%	53
IMR3031	78%	28.7	8-9.59	14.4-15.56	89.6%	69

One thing to note is that these calculations didn't match up with QuickLoad, so I use them as gaurdrails more than anything.

I used the Shooters World and Bison Ballistics recoil calculators because they calculate differently. I also added the Propellant % burnt from QuickLoad because I think that when you take all of that together, you get a different picture, for the data anyway. I know results will vary. But if the recoil calculators are correct, then IMR3031will give the best lowest recoil to fastest velocity ratio. In addition, it will also burn the most powder and has the highest case fill. I didn't do 4198 powders, but based on the MELs article and the Lyman book, that is often a better option for lighter bullets in reduced loads, being a faster burning powder.

Most of my reduced loads have been with the 308, 243 and 27 Nosler. I haven't been trying to do max reductions as much as trying to find low recoil hunting loads. Basically loads for inside 250 yards for smaller framed people with less tolerance for recoil. Except the 27, which is much more of a needless curiosity.