How come do I hit theses speed....

[Mush]

This is a quote from another thread.

Originally Posted by 7mmSendaro

My 300WM prefers IMR4350 (71.0 grains) with 180NAB, 2950fps. I got similar velocity with RL22 but accuracy was not quite as good.

With my gun (24'' Ruger Mark II Sporter), I use same components except primers (mine are WLRM) and I averaged 3017 FPS this week BUT with only 67.5 grains of IMR 4350.

The same day, I tried other reloads but with R22 and at 75 grains I hit AV 3150 FPS (witch seems normal).

Mush

[jwp475]

Different chambers,throats,barrels,stc. will produce different results with the same exact ingrediants,plus the fact that you are using a different primer and perhaps different cases as niether one specified which brand of case that is being used.......

[Mush]

Originally Posted by jwp475

Different chambers,throats,barrels,stc. will produce different results with the same exact ingrediants,plus the fact that you are using a different primer and perhaps different cases as niether one specified which brand of case that is being used.......

I must have have a good combination, 3.5 grains lower charge and about 100 fps more.

Thanks

Mush

[jwp475]

I once changed primers in a 338 win and got more velocity with 2 grains less powder in the same rifle with the same cases and bullets..You do not have the same rifle as the other poster and that is a huge variable

[yotefever]

So does using magnum primers give more speed with about the same pressures or does the pressure go way up?

Thanks,
Mike

[jwp475]

To answer your question that if changing primer and increasing velocity "Does the pressure increase" and the answer is yes.....I did not find the increase in velocity in every cartrdge that I tried this experimint with.There are many variables and that is why you should have as many relaoding manuels as you can possiable obtain and read all of the safe reloading practices and follow them
I was loading a 338 Win.Mag with 76 grains of H-4831 and a 250 grain Partion for 2730 FPS useing a CCI Mag Primer.I switched to a Federal 215 Mag Primer with all other variables the same at the same powder charge and bullet in the same rifle the primer fell out of the case and the velocity hit 2900 FPS.. At 74 grains the velocity hit 2800 FPS...The same experiment in a 375 H&H Mag with Win 760 powder made almost NO difference in velocity with the primer change,so this is not an across the board increase,but it is something to be aware of and take precautions....

[yotefever]

Thanks for the info, that is pretty much what I figured.
I'll have to do some testing of my own and see what happens.
I just picked up the new Sierra reloading book at a Gander store that was moving and had 50% off. Glad I waited to get it.

Mike