Magnum Primers for .45acp and .45colt?

[Cargo]

I ended up with a brick of Federal 155 magnum large pistol primers. Sadly most reloading data for .45 colt and practically all data that I've seen for the .45acp indicate large standard primers.
The .45colt is a Bond derringer so I'm not interested in a hot and heavy load for it. The .45acps are 1911s.

Should I try and start with low end loads and work up or just try and trade them for large standard primers?

[JM7.7x58]

I’ve no experience with LPMP’s. But I have been using SPMP in 38 special loads in my .357 Mag for a while to no ill effect. And, I worked up a load in 40 s&w that is using Rem 6 1/2 SRP’s.

With both loads I ran a ladder test, I backed off my normal powder charge by 10%. I worked back up looking for pressure signs. Didn’t see any.

With the 40s&w I stopped when the gun would function reliably. It has a pretty stiff spring. The SRP load is using two tenths less powder than my standard SPP load.

Your mileage may vary.

JM

[osteodoc08]

If your load isn’t near max, I’d just swap them out personally.

The textbook answer is to lower your charge or start lower and work up.

[Larry Gibson]

If your load isn’t near max, I’d just swap them out personally.

The textbook answer is to lower your charge or start lower and work up.

^^^^^^^^

Better would be to trade them for standard primers as you suggest.

[rintinglen]

Having used Winchester Standard or Magnum primers for almost all my Large pistol primer needs, I don't think you need to be overly concerned using LPMP in place of LPP, always provided that you are not rubbing noses with the top end of the recommended load range. If you are loading to the top, you may need to drop your charge weight by a few tenths, about 5% and consider that your new normal. It may be easier to adjust your load than to find primers to trade for.

[Lloyd Smale]

IF you can trade them do it but the demand for std primers is much higher then for mags. Ive used mag primers in standard rounds many times. Back off at least a grain of powder from max loads and youll be fine. One problem you might run into if there not feds which yours are is that some mag pistol primers are hard to light off and many da guns wont do it shooting da. never had that problem with feds though.

[Cargo]

I know answering questions for newbies can be annoying at times and probably even more so lately with substitutions becoming more common as supplies dry up. I just wanted to say Thank You and your wealth of knowledge is much appreciated.

[PWS]

If you start low and work up there shouldn’t be any pressure issues but one thing I’ve noticed with mags, especially in smaller cases, is that they tend to cause more forcing cone leading in revolvers. Figure it’s due to a hotter, more abrupt start where the bullet doesn’t obturate the same as a gentler shove. Anyway, they’ll make a bang if that’s what you have.

[USSR]

Personally, I would use a powder that benefits by the use of a magnum primer. Such a powder is HS-6, which can be used in both cartridges with the right bullets.

Don

[Bmi48219]

Attachment 272882

I’m not crazy about Winchester primers but I like their “one size fits all” approach. Especially since they were sold at standard primer price. I alway thought the cup metal on Magnum primers was thicker or stronger to hold the higher pressures. These work fine in my 45’s while I have had other brands of SPMs fail to ignite in a few of my pistols.

[BigAlofPa.]

I have trouble with getting a complete burn with blue dot . In 45 colt and 10mm. CCI large mag primers solved the issue. I did try the winchester in 10mm. No go on complete burn.

[bobthenailer]

At one time I bought 25k fed LPM primers for a good price , in my 45ACP i used the same powder charge of Bullseye powder as when using fed STD LP primers , the load was not max 4.5gr BE with a HG 68 200gr SWC. Well i used 15k up in my 45acp handloads ,accuracy was almost identical at 25 yards for a 25 shot group for each primer.

[Petander]

FWIW , I was experimenting with very mild 44 Magnum loads just recently. 44 Special velocities.

This load is a 245 grain bullet with 7.7 grains Vihtavuori N320, chrono says 900 fps with standard LP ( Magtech # 2 1/2) primer.

A CCI 350 magnum primer reads 1050 fps for the same load. I normally use magnum primers only for full house, case full of N110 -loads.

But a mag primer definitely rises velocity and pressure with this fast powder load, fast powders may give a peak... doh... fast.

.


A 10% charge increase can make a min load to a max. When you add a mag primer to double the effect,pay attention.

[Good Cheer]

There's so much overlap (variations) from one brand of primers to the next that it doesn't matter whether you develop your load with so called standard or so called magnum primers. The important thing is that you develop your load. When you change something then re-develop it.

[dogdoc]

I am am just going to stay away from max loads to start with with my magnum primers. If I need max I will use my chronograph to let me know if pressures are likely getting too high

[.429&H110]

There were several magnum primer discussions here over the years. The search engine is your friend! Lyman book calls for one or the the other. I found 350 needful below -30. I primed .44 cases, 300 and 350, shot them, with and without gluegun boolits. The 350 primer is the same "!snap!" but throws a white spark out of the muzzle. One idea in long ago threads was a magnum primer would unseat a Boolit, which would be bad at ignition. 44 has a hard roll crimp, 45 taper crimp... IDKIIM.

[beagle]

IMO, mag primers would be all right providing you aren't close to max loads. I noticed that testing heavy bullets in the .45 ACP that using .45 ACP cases with small primer pockets gave me lower pressure (in my opinion) than the ones with large primer pockets.
The difference would be the "length of the burn" of the primer and would depend on the powder being utilized. That would be the consideration.
I'd try a few loaded lower than max and if they worked. Drive on in this time of primer shortage./beagle

[Petander]

Excuse me for posting sort of off topic but, considering primers and accuracy,I have chronoed average velocities and ten shot spreads for a common 308 moving moose target load.

38 grn N120 with a 100 grain bullet varied from 2780 fps to 2995 fps, Zenit and Fed 215 respectively. Zenit had extreme velocity spread of 45 fps, Fed 75 fps. We also did CCI 200, Winchester Magnum and some others. These two were the slowest and fastest. Win mag had a 150 fps spread. Not good in this case.

The "10" area being 4", a change of 150 fps will change your poi 2 1/2" at 100 meters unless you adjust your point of aim so we really want to know our velocities and primer lots. If a 1 moa gun can vary 1", spread 2 1/2" ... all of a sudden your 4" bullseye is only half an inch wide. With a perfect shot possible,yeah but who shoots perfect shots?

Pictured here is a shooter at 75 meter post, competition is at 100 m.



This is the target. POA is around the beard slot.



The best shooters can repeat 93-95 points out of 100 / ten shots. You need to get that bullseye.

[USSR]

Dang, Petander, if my Ukrainian wife ever wants to move out of the U.S.A., I say we go to Finland.

Don

[Petander]

Dang, Petander, if my Ukrainian wife ever wants to move out of the U.S.A., I say we go to Finland.

Don

Welcome,be my guests.