30x44 load development...

F

feffer

Member
Posted earlier about my case neck wall thickness. The HBR gun was originally set up years ago with a custom .308 barrel. It shot well and I had a few 250's in local competition, one with 14x. But people were beginning to move to shortened .308's to reduce the recoil, so I got a 30x44 barrel. My records show that it never shot consistently, but I'd like to give it another try. It seems I may have set up the cases wrong based on the .330 stamp rather than the real .333 chamber neck size. Some tests a few days ago, indicate that the barrel may shoot well, if I set things up properly. My bullets are .3085 at the pressure ring. I'd like to have minimal clearance cases, just enough to release the bullet w/o spiking pressure. What is considered minimal and safe?

For brass, I have 4 possibilities: .308 Lapua, .308 Federal, .308 Lake City match (fired once) and 30BR Remington (small rifle primer). I have forming dies, K&M mandrel etc, but as I said, I'm not satisfied I set up my previous brass correctly, so what's the best practice for doing it? Also, I did not anneal the brass previously, is that necessary?

Finally, the barrel has a 1:16 twist. I had planned to use either 125 or 135g bullets but these haven't shown good accuracy signs before. OTOH, some 150g bullets which I used extensively in the .308 barrel, shot very well in the 30x44 as well. Should I just surrender and use those, or should I push load development with the lighter bullets?
 
Opinions . . .

feffer said:
Posted earlier about my case neck wall thickness. The HBR gun was originally set up years ago with a custom .308 barrel. It shot well and I had a few 250's in local competition, one with 14x. But people were beginning to move to shortened .308's to reduce the recoil, so I got a 30x44 barrel. My records show that it never shot consistently, but I'd like to give it another try. It seems I may have set up the cases wrong based on the .330 stamp rather than the real .333 chamber neck size. Some tests a few days ago, indicate that the barrel may shoot well, if I set things up properly. My bullets are .3085 at the pressure ring. I'd like to have minimal clearance cases, just enough to release the bullet w/o spiking pressure. What is considered minimal and safe?

For brass, I have 4 possibilities: .308 Lapua, .308 Federal, .308 Lake City match (fired once) and 30BR Remington (small rifle primer). I have forming dies, K&M mandrel etc, but as I said, I'm not satisfied I set up my previous brass correctly, so what's the best practice for doing it? Also, I did not anneal the brass previously, is that necessary?

Finally, the barrel has a 1:16 twist. I had planned to use either 125 or 135g bullets but these haven't shown good accuracy signs before. OTOH, some 150g bullets which I used extensively in the .308 barrel, shot very well in the 30x44 as well. Should I just surrender and use those, or should I push load development with the lighter bullets?
Click to expand...

For the 1:16" twist, if your 150 Gr. bullets are 1.150", or, longer, and presuming that they are FB, you may be disappointed: if they are BT, disappointment is probable. The 1:16" twist should work very well with bullets of up to 1.10" long, including BTs.

You'll likely enjoy best results with total neck-clearance 0.002" to 0.003" - measured across the heel of a seated bullet. I have done well enough with .002", and not less than 0.0015" of TOTAL clearance - in my experience, less is, "a wreck waiting to happen." If truly a 44mm length, the BR brass will be too short.

Make certain that the chamber diameter - just above the extractor-groove - is large enough to accept the virgin brass of choice: many of the older reamers cut a diameter of 0.466-.467", which is too tight for the LAPUA (usually about 0.469 - .4695" just above the extractor-groove, or, web); other brands may also be too large for a good match to chamber cut with a smaller reamer. To avoid problems, check out the chamber and the brass: "small" brass in a "large" chamber (I'm talking diameters here) is better than vice versa.

Flatten the learning curve by trying H-322(Extreme); N-133, or, similar burn-rate powders (first two are very good choices for lighter bullet weights - LT-32 should be excellent also), using a neck-bushing 0.004" smaller that your loaded-round neck-diameter, and a "jam-seat", established by obtaining a land mark which is longer that the lands are wide, start LOW on the powder charge and increase in 0.5 Gr. increments, until the bullets are shooting, "in a hole" (.2" or less), or, until excessive pressure dictates a different powder. If, with decent 125-135 Gr. bullets, it doesn't shoot competitively with either H-322(Extreme), or, N-133, ya probably have a boat anchor. Good shootin'! RG
 
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R.G. Robinett said:
For the 1:16" twist, if your 150 Gr. bullets are 1.150", or, longer, and presuming that they are FB, you may be disappointed: if they are BT, disappointment is probable. The 1:16" twist should work very well with bullets of up to 1.10" long, including BTs.

You'll likely enjoy best results with total neck-clearance 0.002" to 0.003" - measured across the heel of a seated bullet. I have done well enough with .002", and not less than 0.0015" of TOTAL clearance - in my experience, less is, "a wreck waiting to happen." If truly a 44mm length, the BR brass will be too short.

Make certain that the chamber diameter - just above the extractor-groove - is large enough to accept the virgin brass of choice: many of the older reamers cut a diameter of 0.466-.467", which is too tight for the LAPUA (usually about 0.469 - .4695" just above the extractor-groove, or, web); other brands may also be too large for a good match to chamber cut with a smaller reamer. To avoid problems, check out the chamber and the brass: "small" brass in a "large" chamber (I'm talking diameters here) is better than vice versa.

Flatten the learning curve by trying H-322(Extreme); N-133, or, similar burn-rate powders (first two are very good choices for lighter bullet weights - LT-32 should be excellent also), using a neck-bushing 0.004" smaller that your loaded-round neck-diameter, and a "jam-seat", established by obtaining a land mark which is longer that the lands are wide, start LOW on the powder charge and increase in 0.5 Gr. increments, until the bullets are shooting, "in a hole" (.2" or less), or, until excessive pressure dictates a different powder. If, with decent 125-135 Gr. bullets, it doesn't shoot competitively with either H-322(Extreme), or, N-133, ya probably have a boat anchor. Good shootin'! RG
Click to expand...
Thx RG, for the detailed answer. I did some measurements and dug though my inventory mostly bought about 12 years ago. I've collected so much stuff, I wonder what I was thinking! As a bullet guy, you probably know Bob Cauteruccio. I bought my 30 cal bullets from him and have a decent supply of 125 and 150g FB left. The 150g is about 1.08" long and the 125g is about .980".

As far as the chamber dimensions, my chamber cast mics .4723 just above the extractor groove, and the neck is .3330". What I said was 30BR brass was actually .308 Win with small rifle primer pockets made by Remington (R-P 30 REM headstamp), so it's plenty long enough. It is .464" just above the groove. I have only about 40 virgin Lapua .308 cases left and as you indicated, they are .4693" I have a larger quantity of once fired Lake City brass that mics .470" and about 80 virgin Federal .308 cases that mic .465" and 60 virgin Norma .308 cases. So any of these would probably work. I'm gravitating to using either the Lapua cases or the 30BR (.308) cases. Does primer size make a difference? I don't know how current HBR guns are set up or whether there is a preference for using LR or SR primers.

My earlier cases, made 12 years ago, have neck clearance ranging from .0030-.0045" probably a bit too much. I'll shoot for .002 this time around. I've forgotten the exact case forming process, I used before, but I think it involved cutting off some of the excess length, forming a false shoulder which will fit tight when the bolt is closed and fire-form with yellow corn meal (groups better than cream-of-wheat). Then use a mandrel to expand and K&M tool to turn the necks. I did NOT anneal my brass before, but would that be a good idea? Before or after fire-forming?

I have V-133 and H-322 (Aus) left from years ago, but I kept it in good conditions, so I'm thinking it should be fine if I start low. I also have a good supply of 8208 but maybe that's better for the 6PPC? This barrel may well be anchor material, but I should give it a decent try first. In any case, it'll probably only be used for practice and local competition.
 
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I will respond (in RED) within your quote.

"Thx RG, for the detailed answer. I did some measurements and dug though my inventory mostly bought about 12 years ago. I've collected so much stuff, I wonder what I was thinking! As a bullet guy, you probably know Bob Cauteruccio. I bought my 30 cal bullets from him and have a decent supply of 125 and 150g FB left. The 150g is about 1.08" long and the 125g is about .980". " Bob makes excellent bullets - at these lengths, both should prove useful via you 1:16" twist.

As far as the chamber dimensions, my chamber cast mics .4723 just above the extractor groove, and the neck is .3330". What I said was 30BR brass was actually .308 Win with small rifle primer pockets made by Remington (R-P 30 REM headstamp), so it's plenty long enough. It is .464" just above the groove. I have only about 40 virgin Lapua .308 cases left and as you indicated, they are .4693" I have a larger quantity of once fired Lake City brass that mics .470" and about 80 virgin Federal .308 cases that mic .465" and 60 virgin Norma .308 cases. So any of these would probably work. I'm gravitating to using either the Lapua cases or the 30BR (.308) cases. Does primer size make a difference? I don't know how current HBR guns are set up or whether there is a preference for using LR or SR primers. With this web diameter (.4723"), any of the cases should work.
One nit-pick: the Rem. small primer-pocket brass should be referred to as .308UBR (the unprimed version) - it is distinctly different than 30/6/7BR. I can get my head around 308BR, however, calling it 30BR could confuse those who are learning, or, are unfamiliar with the differences: the 30BR remains a "WILD-CAT", based upon the 22/6BR, for which, Remington originally offered only the full length .308 (UBR) small primer brass. Initially, forming 22/6 BR brass required serious work. Remington may also have offered a primed version of the small primer .308 length brass.:eek: The salient feature being that for a 30x44, THE BR case is too short . . . end of rant.:p;)

I have enjoyed some success using the .308UBR brass - from 'short' 22 & 6 BRs, through 30x44 and 30x47 chambered rifles - mostly the latter - and several wild-cat cartridges, from 6/250 Ackley Imp., up to full capacity - I have never been disappointed. :eek:

My earlier cases, made 12 years ago, have neck clearance ranging from .0030-.0045" probably a bit too much. I'll shoot for .002 this time around. I've forgotten the exact case forming process, I used before, but I think it involved cutting off some of the excess length, forming a false shoulder which will fit tight when the bolt is closed and fire-form with yellow corn meal (groups better than cream-of-wheat). Then use a mandrel to expand and K&M tool to turn the necks. I did NOT anneal my brass before, but would that be a good idea? Before or after fire-forming? I know nothing of annealing brass. :p

I have V-133 and H-322 (Aus) left from years ago, but I kept it in good conditions, so I'm thinking it should be fine if I start low. I also have a good supply of 8208 but maybe that's better for the 6PPC? This barrel may well be anchor material, but I should give it a decent try first. In any case, it'll probably only be used for practice and local competition." With the 150 Gr., slower powders - H-4895;Win. 748; N-135 may also prove very useful. RG
Last edited by feffer; 12-12-2014 at 07:57 PM.
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