I know that they are not required but its all i had so i loaded 130 gr BTs over 58.5 gr. H4831SC. Anyone think I may have a pressure problem loading so close to max (60.0 gr)?

There are a lot of IFs and BUTs in giving you a straight answer.Load 2 more cases with that primer;one with 56.5gr. and one with 57.5gr. Starting with the 56.5gr fire and examine for pressure signs. Do the same with the 57.5gr if the 56.5 was safe.From the results you get make a decision if the 58.5gr. looks safe enough to shoot or not. roger

I know alot of friends who use the Magnum primer in the 270win with no pressure problems

Hey M7LSS, Bartsche has provided the correct answer. Only change I'd make would be loading in 0.5gr increments.
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However, I have a question for you. From your post it "gives the impression" that you just randomly selected 58.5gr. My question to you is "why" would you not develop the Load from below in incremental steps - as ALL the Load Manuals specify?

I think your question (and the answers you've received thus far) is based on an errant premise, i.e. that the load would NOT have pressure problems if a "standard" primer were used. Apparently, you have no data, other than from a reloading manual, upon which to base that assumption. The answers you've received contemplate the difference between a "safe" load with a "standard" primer and that same load with a "magnum" primer. However, you are asking not about an actual substitution in a load of known performance, but rather a given load of unknown performance.

Without belaboring it futher, I would advise that (1) 58.5 grains of H4831 would typically be a reasonable load in most .270's, and (2) the use of a "magnum" force primer might or might not create a discernable increase in pressure, however, if there were an increase it would not reach the "unsafe" level.

Shoot 'em and see what you get. At the very worst, it would be loosened primer pockets by the second or third loading.

I shoot that load, with Mag primers, in both an A-Bolt and a Rem700 without any pressure signs. Your gun may be different. Start lower and work up.

quote:

Originally posted by model7LSS:
I know that they are not required but its all i had so i loaded 130 gr BTs over 58.5 gr. H4831SC. Anyone think I may have a pressure problem loading so close to max (60.0 gr)?

That load is under what is normally permissible with the 130-grain in the .270 Win. As a matter of fact, I have not been able to get enough H4831 behind a 130 in the .270 Win. case to cause damage to cases.

BUT the idea of starting lower and working up 0.5-of a grain at a time is sound!! ALL rifles ARE INDIVIDUALS....

It depends on your rifle, work up. FWIW my standard 150 gr loading for the 270 uses 58.5 grs and a CCI250 or a FED 215, just under 2900 no signs of pressure in my rem 700.

I'd just shoot them.....I've never been able to get enough H-4831 in a .270 case with a 130 grain bullet to produce any signs of pressure.

Well, what i apparently forgot to mention was that i loaded these for my 44byf mauser that was sporterized way back when. Little concerned about hot loads in a 65 yo rifle.

You'll never know if they are "hot" loads unless you work up until you see signs of excess pressure, your rifle might digest 60 or more grains and never show a sign. Start low and work up, it doesn't matter if it's a mauser or a weatherby.

In a Handloader article, Barsness(sp?) found he got slight better performance with magnum primers in the 270. I have been loading for the 270 for some decades now, & seriously doubt you will have any problem with your load using mag primers. The 270 was designed from day 1 for high pressure performance and I have always found my best groups were not the modest ones!