New Reloader Looking for Help on Fire Forming New Brass for 7mm-08

[Notorious BEN]

I'm new to reloading and have a question for fire forming some new Starline 7mm-08 brass I have. The goal is just to get 5 pieces fire formed to get an average water capacity for GRT.

Currently all of my powder is Vihtavouri and I have a box of Barnes 139gr LRX on the way to see how they shoot in my rifle. Also I realize that getting them to group good is a part of the load development process, but I want to make sure my 1:9" twise barrel will stabilize them (it should anyways).

Here's my question. There isn't much data out there for Vihtabouri powders in 7mm-08 and their app lists a range of 39.4-43.1gr for N150 and 39.2-42.7 for N540. On the other hand there is a lot of data out there for IMR 4350 and a local reloading supplier has some for $83/pound. Should I just see what GRT says for the Vihtavouri powders that I have and pick the one with the biggest range and do 1-1.5gr under their load calculation for 62,000 psi (planned max charge weight pressure) or just buy the IMR 4350, look at everyone's data to get a safe max charge weight, load up 5 rounds, and measure the velocity?

I would label each case and measure it's length before loading to see how much they stretch and also look at if they are all the same length after firing. I could always increase the powder charge using GRT after firing and measuring the water capacity of those 5 cases too to play it safe.

The main goal here is to learn, but do it safely. Thanks!

 

[TaperPin]

GRT suggests a starting load reduction based on pressure below and gives reasons to be careful working up to maximums.

If you look at various manuals, often suggested starting loads are a 5% reduction from max loads based on weight, so closer to 2 to 2-1/2 gr off of max for your loads. Most guns are similar and can use similar max loads, but some aren’t as forgiving. Every year some guys go straight to max loads and end up sticking a case in the chamber, blanking primers, or blowing primers.

 

[HandgunHTR]

If all you are doing is fireforming them to get a volume for your brass/chamber combo, just use the VV powder and pick a low/medium charge.

$83/lb for IMR4350 is robbery.

Unless you plan to only shoot virgin brass in your rifle, your best bet is to buy some cheap bullets (I recommend Hornady 139 grain BTSP), load all your brass with a moderate powder charge (I usually go 1.5 grains below max with whatever powder I have that isn't being used for something else) and shoot it all. Use that shooting to get your scope dialed in, get used to running the rifle and to ensure everything is tight.

Once you have all the brass fired in your rifle, then you can start load development.

 

[Notorious BEN]

If all you are doing is fireforming them to get a volume for your brass/chamber combo, just use the VV powder and pick a low/medium charge.

$83/lb for IMR4350 is robbery.

Unless you plan to only shoot virgin brass in your rifle, your best bet is to buy some cheap bullets (I recommend Hornady 139 grain BTSP), load all your brass with a moderate powder charge (I usually go 1.5 grains below max with whatever powder I have that isn't being used for something else) and shoot it all. Use that shooting to get your scope dialed in, get used to running the rifle and to ensure everything is tight.

Once you have all the brass fired in your rifle, then you can start load development.

Yeah, the price of the IMR 4350 was a bit shocking...

I think what I'm going to do is see if either shop in the area has some 139gr Interlocks and I'll load up 5 with 43gr and 5 with 44 gr of N160

Hornady lists a little more than 43gr of N160 for 2500 fps and 2700 fps is between 46gr and 47gr. The max in their data is above both those charge weights by more than 4gr so if the 43gr has a velocity of 2700+ fps, I know to hold off on the 44gr and I can always pull the bullets and recharge based on GRT.

I appreciate the feedback!

 

[steelheadmike]

All the above advice is good. Also remember that monometals may have different max charge weights that lead bullets so you may get different results with the LRX vs BTSP.

VV and Hornady have data for N140, N150 (well, Hornady doesn’t for some odd reason), and N160. VV has data for N550 and N540. I’ve just started to play around with the Viht powders and have been happy with them so far. Although I haven’t used it, N540 is probably about right for the 139gr bullets. The N550 seems to be good for the 150s.

Another good resource is to email Berger. They will send you data for Viht powders as they are owned by the same parent company.

Although GRT can give you some good starting points, it seems like some of their powder data for Viht powders can be a little wonky.

And, read the simple load dev thread. It will save you a lot of running in circles.

 

[Notorious BEN]

Thanks!

My next step is to figure out how to add a bullet into GRT, but I need to see if you can put in whether they are cup and core or monolithic. I am also working up potential loads for my 243 and I found the directions on Discord where I believe someone added the 95gr LRX that I also have in my order coming to try alongside the Hornady 103gr ELD-X. Either way I have been searching on Discord for their how to's and will post over there to make sure I'm doing it right.

For the Hornady data I have using N160, they have it for all of their 139gr 7mm bullets so the Interlock and CX have the same charge weights listed.

 

[steelheadmike]

Thanks!

My next step is to figure out how to add a bullet into GRT, but I need to see if you can put in whether they are cup and core or monolithic. I am also working up potential loads for my 243 and I found the directions on Discord where I believe someone added the 95gr LRX that I also have in my order coming to try alongside the Hornady 103gr ELD-X. Either way I have been searching on Discord for their how to's and will post over there to make sure I'm doing it right.

For the Hornady data I have using N160, they have it for all of their 139gr 7mm bullets so the Interlock and CX have the same charge weights listed.

I’m interested to see how the N160 will work with the 139gr. Could be a tad slow for the light bullets, but if it’s what you have, go for it.

It was a little wierd that Hornady lists N140 and N160 but not N150, which seems about perfect with them but it’s not the only oddity in the Hornady data.


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[Notorious BEN]

I’m interested to see how the N160 will work with the 139gr. Could be a tad slow for the light bullets, but if it’s what you have, go for it.

It was a little wierd that Hornady lists N140 and N160 but not N150, which seems about perfect with them but it’s not the only oddity in the Hornady data.


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I agree and I'll probably start with the 2nd lowest charge weight. I thought about it and I may look at what my Berger book has for the 140gr Hunter and see what they cost.

So far the attarctive thing about N160 is there is a wider range than what I'm seeing on N150. I should be fine even at the lower charge weights with N150, but I'm new and I look at the wider range of N160 as a safety precaution too.

 

[Notorious BEN]

Ok here's where I'm at as of right now. I bought both N150 and N540 because from what I could tell, they were powders to consider after measuring water capacity from some Nosler brass that were factory loads.

I initially was going to focus on loading the 150gr ELD-X, but wanted to give the Barnes LRX a try since I'm currently using their 120gr TTSX factory loads for hunting (100 yard shots typically here in the Texas Hill Country).

I have data for the Sierra Matchking 150gr from the Vihtavouri app using N150, N540, and N550 and found additional data for those same 3 powders for a 150 grain jacketed bullet in a reloading manual I have.

Vihtavouri lists 36.4-41.5gr and the manual has a range of 34.4-38.1gr for N150.

My thoughts are to start with some 150gr Sierra Matchkings and load 35.4gr, 35.8gr, and 36.2gr (average of 4.4gr between min and max and once again I can pull bullets if the 35.4gr shoots 2700 fps) and see what those get me.

Note: I have always wanted to hunt Pronghorn and have a friend that helped get me back into hunting a few years ago that has discussed the basics of planning DIY western hunting trips. That's the reasons for focusing on higher BC bullets and I prefer Barnes, but will go with bonded or cup and core with a locking ring of some sort to use what rifles I already have.

Per Ron Spomer, "Beware of the one gun hunter" lol.

 

[N8funk83]

Check out Sierra’s 7mm-08 data for the 160 TMK with H4350. Looks spicy.

 

[N2TRKYS]

I find fireforming correct headstamped brass to be a waste of time and components. Ramshot Big Game powder is the easy button for the 7-08. I’m getting 2850 fps with a 140 grain Accubond out of a 20” barrel using Big Game powder and a WLRM primer.

Also, don’t overlook the 120 grain NBT. It’s a tough little bullet. I have a load that’s traveling 3000 fps out of the same 20” barrel. That’s with Varget. Big Game would get alittle more velocity.

 

[Notorious BEN]

I find fireforming correct headstamped brass to be a waste of time and components. Ramshot Big Game powder is the easy button for the 7-08. I’m getting 2850 fps with a 140 grain Accubond out of a 20” barrel using Big Game powder and a WLRM primer.

Also, don’t overlook the 120 grain NBT. It’s a tough little bullet. I have a load that’s traveling 3000 fps out of the same 20” barrel. That’s with Varget. Big Game would get alittle more velocity.

I'm just wanting to get water capacity for GRT. I currently have some of the NBT 140gr in my Midway cart just because the 120gr is sold out.

 

[N2TRKYS]

I'm just wanting to get water capacity for GRT. I currently have some of the NBT 140gr in my Midway cart just because the 120gr is sold out.

If you like Nosler bullets, don’t forget to check Nosler’s website for the seconds and overruns. You have to catch them in stock, but usually worth the time.

 

[Finaddictions]

That 140 NBT is a pretty underrated bullet. The 120 gets lots of love, but the 140 is just as or more impressive in my opinion. I had a string of 8 deer in a row dead where they stood with rib shots. Sure love the no tracking deal, and that bullet is scary accurate too.

 

[Notorious BEN]

I like the Nosler Ballistic Tips and I have 7 boxes of their factory loaded 243 ammunition that I'm saving the brass to test out a couple different bullets and powders to see what I can get velocity wise before I get some Peterson brass.

I bought the Starline 7mm-08 brass to do something similar and to have a Texas HIll Country load that's going to be more for the 100-150 yard shots here. We do have free ranging Axis deer and that's where the 7mm-08 really shines. A good placed 243 shot can kill them, but they're a little tougher than a whitetail deer and I like having the extra energy.

The doe on the ground and on the tailgate are the same.

 

[wind gypsy]

Personally if I wanted to load n150 and didn't have data, i'd just reference the charge weights for Varget and start a fair margin below max.

When did GRT become a primary tool for newbys coming up with loads?

 

[Notorious BEN]

Personally if I wanted to load n150 and didn't have data, i'd just reference the charge weights for Varget and start a fair margin below max.

When did GRT become a primary tool for newbys coming up with loads?

I bought some Nosler 140gr ballistic tips for the reason that I have a few books and online resources/Vihtavouri app that I can come up with a good starting point. I'll post my proposed starting points later after I can look at everything.

I've been following along with a precision reloading series on YouTube where the guy goes into how to use it properly. Between that and some other resources, I feel pretty safe.

I plan to double check my work via Rokslide and a reloading group I'm a member of on Facebook before I do any actual loading just to be safe.

 

[WhoGarrDen]

If you're still looking at powders, Natchez has free hazmat on $99+ orders. You'll still pay $20 in shipping, but if you snag two bottles of powders (highly recommend having at least 2 powders to try, if not 3) you'll come out way ahead of paying that $80/bottle local charge. Add in some CCI 200 LRP's as those are on a good sale there as well (for now).

 

[Dave Thomas]

If you have n150 and n540 I don't think you'll have to look any further for powders to use. I used n540 in my 7mm08 with 140's and loads were neck in neck with varget.

 

[Notorious BEN]

If you have n150 and n540 I don't think you'll have to look any further for powders to use. I used n540 in my 7mm08 with 140's and loads were neck in neck with varget.

The other 3 that I have are for my 243 loads I'm working on.