W296 needs mag primers???

[Sharkbite]

I was at my LGS a cpl days ago and overheard someone talking about 300 blk loads. He was saying that W296 (and im guessing H110 as well) need magnum primers for consistant ignition.

My load of 296 with a 125gn bullet had some pretty extreme spreads in velocity. Would mag primers help with this. Nosler 7 says standard primers FWIW.

Anybody have an answer???

[tallburnedmidget]

I was at my LGS a cpl days ago and overheard someone talking about 300 blk loads. He was saying that W296 (and im guessing H110 as well) need magnum primers for consistant ignition.

My load of 296 with a 125gn bullet had some pretty extreme spreads in velocity. Would mag primers help with this. Nosler 7 says standard primers FWIW.

Anybody have an answer???

In my experience it is always the wisest coarse of action to avoid local gun store advice when there is published information available for you to follow. All published loads I have run across or 300BLK identify standard small rifle primers as the primer to use. Can you use magnum primers? Sure but you will likely not find many (if any) published loads specifying their use.

It has been reported that using annealed brass and a light crimp helps with some of what you are experiencing. The only way to tell for sure is for you to give it a shot and see how your rifle and loads perform.

Good luck and beware the local gun store talk

[Sharkbite]

Exactly my thoughts. Hence the question to the masses here. More info makes for better decisions.

LGS talk is always suspect... Sigh

[tfbit]

My sig is there for a reason. I was using a load of 19.8gr of H110 with a CCI450 primer behind a 110gr V-Max with no problems. One day, after reading that CCI41s were ballistically the same as CCI450s, I switched to CCI41s with the same load and got an extra 50FPS, very bad SD, loose primer pockets, and nasty ejector swipes. I had to drop the powder down to 19.0gr with CCI41s to get back to normal velocities and no pressure signs. Only explanation is that the CCI41s caused the H110 to burn better and faster than the CCI450s. Pictures of brass here:

viewtopic.php?f=141&t=85240&start=10#p797797

[AR-300]

CCI400s with H110 work fine for me

[Garrett]

More consistent? Maybe. Don't know.

But a while back, I loaded up some ammo using the same charge of 296 and a 220 gr. SMK, changing only the primers. At the time, I ran CCI #41, CCI#450, and WSR. I then shot 20-shot groups at 100 yds., shooting over the chronograph.

Results:
WSR had an average velocity of 1026 with a spread of 76 fps. and an SD of 22.
CCI#41 had an average velocity of 1006 with a spread of 203 fps. and an SD of 48.
CCI#450 had an average velocity of 1003 with a spread of 94 fps. and an SD of 17.

CCI#41 has a harder primer cup, but is it considered a "magnum" primer? I'm not sure. I know it did give the least consistent results, both on paper and over the chronograph.

CCI#450 gave the best grouping and chrono results were close to WSR in consistency.

WSR, the non-magnum primer seemed to show the best consistency and also the highest velocity. It had a slightly larger group, mostly due to one flier.

You can see the groupings below.

[talonxracer]

With your 296 and 220smk loads did you use any polyfill to take up dead air space and keep the powder against the base of the case and the primer? I had dismal accuracy/grouping with h110 and subs until I added polyfill, then the groups closed way up. I was using Fed 205's, I recently tried the CCI41's and had to drop powder charges even further to stay subsonic and the groups opened way up and nothing helped close them.

[oldpapps]

Go with what YOU know to be right.

My experience...
Cold slows down burn.
Some powders are hard to get going.
Combine the two above and a Magnum pistol primer may be prudent.

A 'small rifle or large rifle' primer has never failed me in this regard in the last 50+ years.
Standard strength small pistol primers have been touch and go with 296 and (very cold weather) 2400.
When I was in central Montana, my winter loads were always mag primers and 2400 (back when I shot little pistols - .357s). Summer loads, worked well with standard strength primers. Guess I could have used those 'all-in-one' primers

Point being, if it ain't broke, don't fix it.

Talk is cheap and many times has the same value.

Load with care,

OSOK

[exx1976]

I use regular CCI 41's with W296 in my SMK 125 loads. No problems.

My 223 AR loads are CFE-223 with Tula KVB223M primers.

Both the KVB223M and CCI#41 are "AR primers", meaning they are standard charge, harder cup.

I've not had a problem with either.

Not to say that things maybe wouldn't be improved with the use of a Magnum primer, but I've never tried, and I'm plenty pleased with my loads the way they are.

[talonxracer]

Go with what YOU know to be right.

My experience...
Cold slows down burn.
Some powders are hard to get going.
Combine the two above and a Magnum pistol primer may be prudent.

OSOK

Temperature is not considered as often as it should be.