LR primers in the 44 Magnum

[Larry Gibson]

Thought I’d just start a new thread instead of digging up the old one. Got a break in the weather so I conducted the test of LR primers in the 44 Magnum. SAAMI MAP (Maximum Average Pressure) for the 44 Magnum is 36,000 psi with a MPSM (Maximum Probable Sample Mean) of 38,800 psi.

The test was conducted with a Contender pistol and the Oehler M43. All tests are 9 or 10 shot test strings. I had 2 FTF with the Contender and 2 of the primers. I used two loads;

RCBS 44-250-K cast of WWs + 2 %tin with a BHN of 16, sized .430 and lubed with Javelina
WW Super 44 Magnum cases (new) with primer pockets reamed for LR primers
WW Super 44 Magnum cases (new) with standard primer pockets with control loads
OAL; 1.711”
Powders; Alliant 2400 (21 gr) & H110 (23 gr)
Results listed as; primer/average velocity (fps)/SD/ES/average PSI (M43)/SD/ES

H110 load;
Control load;
WLP/1400/24/78/21,700/1,200/3,600

LR primer loads;
Rem 9 1/2/1466/47/112/25,200/3,500/8,500
CCI 200/1390/49/141/22,100/1,500/4,200
CCI #34/1507/35/107/28,300/3,000/9,000
WLR/1506/26/85/28,500/2,300/6,000
Fed 215/1544/12/36/31,600/1,500/4,100

Here we see all the psi’s within SAAMI proscribed MAP. We find the control load with WLP primers to be relatively mild. The hotter Fed 215 magnum LR primer produced the most consistent internal ballistics and the highest psi with the highest velocity with H110. No pressure problems observed with using the LR primers in this load with H110 powder.

Alliant 2400 load;
Control load;
Fed 150/1542/18/51/30,800/1,000/2,700

LR primer loads;
Rem 9 1/2/1603/13/37/34,700/500/1,200
CCI 200/1589/20/46/33,000/1,800/5,000
CCI #34/1634/10/27/37,900/1,900/5,500
WLR/1633/8/22/37,600/1,000/2,600
Fed 215/1641/13/29/41,200/1,900/4,100

Here we see some LR primers (the “soft” 9 ½ & 200) are OK with this load keeping the psi under the SAAMI MAP/ However, when magnum level LR primers are used we see the psi going Over the MAP and the Fed 215 psi going over the MPSM. Note the very good internal ballistics with this load of 2400 with all the primers tested. Obviously this load is burning very efficiently in the 30K to 41K psi range.

Obviously the use of LR primers raises the psi in both loads. I’ll leave the question of “is it dangerous” for you all to decide. Note; I was not able to seat LR primers in standard pocket cases without severely scrunching them so the Contender would close or the cylinder of my Colt Anaconda or Ruger BHFT would rotate. To use LR primers in the WW Super cases really requires the primer pockets be reamed out.

Larry Gibson

[felix]

Good show, Larry! ... felix

[stubshaft]

Good job Larry. I use LR and SR primers respectively in my pistol cartridge loads for my Marlin rifles.

[Johnk454]

Similar test, yet different caliber from eight years ago:

http://www.leverguns.com/articles/johnk/primertest.htm

The real issue is to make sure a fellow doesn't work up a load with say, a pistol primer and then switch to a rifle primer only to discover a much more vigorous load ensued...

[runfiverun]

it does appear that the hotter magnum primers do show wider pressure swings.
i would wonder if they could push things too far.
the standard rifle primers with the high density powder loads actually look pretty good.
i'd be interested to see the results on target from a bench gun.
the standard deviation and extreme spread in velocity are misleading in terms of [relating to] pressure though.
who would expect 2,000 psi to only come to 30 fps in velocity??

i have noticed some loads of 2400 to be more accurate with rifle primers [in rifle cartridges]
than revolver primers.
and oftentimes a filler will reverse this.
i think because the rifle primer has enough "oomph"to disturb the fillers purpose.

i have been working with powders slower than h-110 in many of the "magnum" and supermagnum cases [aa-1680 and aa-2230] and some swaged bullets up to 350 grs.
the large rifle primers have been on my mind for a bit, but this definately is a direction i will have to take now i'm gonna have to go pull some 315 gr bullets and start again.

[Cariboo]

thanks Larry, very informative

[MakeMineA10mm]

Actually, with the H110 load, the WLP showed the lowest pressure deviation and spread.

I must have missed the previous thread that instigated this investigation? As it stands, it's good data, and just tells me - there's no sense in spending the time and effort to ream out my 44 pistol brass to take rifle primers.

Pistol caliber carbines are intended to work with pistol primers, so no need from that standpoint... Is there a capacity issue, where we're running out of case volume for the powder, and therefore, we need to add some juice via the primer? (I could see that with a bulky slow powder for this application, such as IMR-4227, which always has a few thousand PSIs left to reach max when the case is full to the point of mild compression of the powder.)

[Bwana]

Actually, with the H110 load, the WLP showed the lowest pressure deviation and spread.

I must have missed the previous thread that instigated this investigation? As it stands, it's good data, and just tells me - there's no sense in spending the time and effort to ream out my 44 pistol brass to take rifle primers.

Pistol caliber carbines are intended to work with pistol primers, so no need from that standpoint... Is there a capacity issue, where we're running out of case volume for the powder, and therefore, we need to add some juice via the primer? (I could see that with a bulky slow powder for this application, such as IMR-4227, which always has a few thousand PSIs left to reach max when the case is full to the point of mild compression of the powder.)

the thread you missed was this one: http://www.castboolits.gunloads.com/...s+pistol+cases

The point wasn't about "need" except perhaps you might be in a situation where all you had were LR primers to load "handgun" cases. More to the point it showed another area of possibilities which might interest some people.

[Grandpas50AE]

I noticed the best velocity deviation and spread was achieved with the rifle primers and 2400, and the pressure levels could easily be mitigated by easing back half a grain or so on the powder charge. I had thought of trying this many times over the past 10 years, especially after Winchester dropped the magnum primer designation and went with just WLP and WSP for the pistol primers. I load H110 in several pistols, and H110 is a slow-burning powder.

Nice data Larry. Thanks for posting.

[44man]

Good show Larry. Very informative.
I hope fellas remember I use a standard primer in the .44 just to keep the boolit in the brass as long as possible in revolvers.
I hope if anyone tries rifle primers to make sure the pockets are reamed.
I see no reason to use them. Looks like a lot of pressure ES's.

[Shuz]

Nice job,Larry! very thorough.

[cbrick]

Larry, from the other thread I take it the grouping was done at 50 yards? What were the results of group testing between standard pistol and rifle primers?

The rifle primer raised the pressure an average (rounded off) of 10,000 psi from the control load proving my point that the less experienced should not play with this and with top end loads very undesirable results are possible. An increase of 10,000 PSI with the same powder charge is not insignificant.

H-110 control load 21,700 PSI
Fed 215 31,600 PSI

2400 control load 30,800 PSI
Fed 215 41,200 PSI

The question is not can it be done, of course it can the question is should it be done. I'll stick with the purpose of my posts in the other thread, those without the experience to fully understand possible consequences need to also read of possible dangers.

Aside from the safety issue I’m eager to see the results the group testing.

Rick

[Larry Gibson]

the thread you missed was this one: http://www.castboolits.gunloads.com/...s+pistol+cases

The point wasn't about "need" except perhaps you might be in a situation where all you had were LR primers to load "handgun" cases. More to the point it showed another area of possibilities which might interest some people.

Thanks for posting the original thread. I should have done that I suppose just so the background for the test could be understood. Thanks

Larry Gibson

[Larry Gibson]

Good show Larry. Very informative.
I hope fellas remember I use a standard primer in the .44 just to keep the boolit in the brass as long as possible in revolvers.
I hope if anyone tries rifle primers to make sure the pockets are reamed.
I see no reason to use them. Looks like a lot of pressure ES's.

Bwana had the ability to ream the primer pockets for the LR primers and it was a useful project test for those who may have a rifle/handgun that can handle the pressures. Also for those who ask "if you have to, can you?" it provides the information that the loads really need to be worked up as mentioned.

The pressure ES aren't really that large and are within SAAMI specs for psi variation of an acceptable load. One thing I've learned in the multiple tests I've run with numerous cartridge/loads is that within acceptable variation there isn't a correlation between psi ES and fps ES. Seems like there would be but there isn't. It’s one of those theories of this game that sound good but don't pan out in actual testing.

BTW; SAAMI uses a constant from the Biometrika Tables for Statisticians based on the sample size for 90% confidence to determine the maximum allowable psi ES. If we use the H110 control load for an example;

H110 load;
Control load;
WLP/1400/24/78/21,700/1,200/3,600

We find the maximum allowable psi ES would be 6,192. Even the largest psi ES of; CCI #34/1507/35/107/28,300/3,000/9,000 was still within the maximum allowable psi ES (15,480) for that load with that psi SD.

However, to actually determine what is an acceptable psi variation range SAAMI also uses a maximum allowable SD for acceptable loads. This is 4% of the MAP. This is 1,440 psi SD for the 44 Magnum. We see both control loads with the LP primers are within this allowable SD variation. Only 2 of the Alliant 2400 loads with LR primers are within the allowable SD variation. None of the H110 loads with LR primers fall within the SAAMI acceptable psi SD variation range.

Larry Gibson

[felix]

One thing I've learned in the multiple tests I've run with numerous cartridge/loads is that within acceptable variation there isn't a correlation between psi ES and fps ES. Seems like there would be but there isn't. It’s one of those theories of this game that sound good but don't pan out in actual testing. ... Larry

You should not have expected it, Larry! Energy is expended throughout the entire system which contains components that are never consistent for each shot. Always consider the ACCELERATION of each component at each moment. F = M*A ... felix

[Larry Gibson]

Larry, from the other thread I take it the grouping was done at 50 yards? What were the results of group testing between standard pistol and rifle primers?

The rifle primer raised the pressure an average (rounded off) of 10,000 psi from the control load proving my point that the less experienced should not play with this and with top end loads very undesirable results are possible. An increase of 10,000 PSI with the same powder charge is not insignificant.

H-110 control load 21,700 PSI
Fed 215 31,600 PSI

2400 control load 30,800 PSI
Fed 215 41,200 PSI

The question is not can it be done, of course it can the question is should it be done. I'll stick with the purpose of my posts in the other thread, those without the experience to fully understand possible consequences need to also read of possible dangers.

Aside from the safety issue I’m eager to see the results the group testing.

Rick

The groups at 50 yards were good, bad and ugly. I wasn't really trying for best accuracy being more concerned with collecting the measured data. I always shoot better not shooting through screens but I was shooting fairly well. The reason for the inaccuracy is with this Contender barrel accuracy any BB cast bullet cast bullet goes south over 1400 fps. With a FB'd cast bullet like the RCBS bullet used accuracy is usually good through 1480 - 1500 fps. Over that and it goes south. That's what we see here, the H110 load at 1400 fps gave a 10 shot group of 1.95". The Alliant 2400 group at 1542 fps and a much higher psi gave a 3.6" group. The higher velocity/higher psi loads accuracy with the LR primers got down right ugly

Larry Gibson

[Larry Gibson]

One thing I've learned in the multiple tests I've run with numerous cartridge/loads is that within acceptable variation there isn't a correlation between psi ES and fps ES. Seems like there would be but there isn't. It’s one of those theories of this game that sound good but don't pan out in actual testing. ... Larry

You should not have expected it, Larry! Energy is expended throughout the entire system which contains components that are never consistent for each shot. Always consider the ACCELERATION of each component at each moment. F = M*A ... felix

I haven't expected that since I learned it some time ago......was answering a question. However, it does seem logical to many that there should be a correlation. As we see however, there isn't for the reason you mention.

Larry Gibson

[pdawg_shooter]

Good report Larry. I have used CCI 200s with H110 in my 29 Smith for years. All my primer pockets are cut to use LR in my 44s.

[TNFrank]

To use LR primers in the WW Super cases really requires the primer pockets be reamed out.

Larry Gibson

I was going to say, LR are a bit longer then LP so you'd have to make the primer pocket deeper or you'd be getting high primers. Good info though, thanks.

[cbrick]

Thanks larry, good testing and solid data to examine. Very worthwhile and informative.

Rick