Scared myself with chrony

[onlybrowning]

I had a chance to chrono my favorite hunting load for my .270 the other day. It is 59.0 grains of H4831sc, Rem brass, fed.210M, and of course, a 130 grain Nosler ballistic Tip. It came over teh chrony at 3157fps. This is a regular Browning A bolt with only a 22" barrel. Most manuals put this load at about 3000 fps with a 24" test tube! Whodathunkit.

Now, I have killed quite a few deer with this load, all have been one shot bang flops. My question is this: If I was to shoot a close range shot, I would be over the max velocity for impact for this bullet. Should I switch to an AccuBond? Or do I not mess with a great thing. Note, the closest deer shot with this laod was at about 80 yds.

Tomorrow I will shoot some 150's I have of the same design, maybe they will be much faster than the book as well! (but under 3000fps)

 

[JD338]

Nosler list your load at 3124 from a 24 " barrel so you are doing quite well
with your 22" Browning A Bolt.
Give the 130 gr AB's a try, the results may be better than you think.

JD338

 

[steve4102]

Give the 130 gr AB's a try, the results may be better than you think.

JD338

+1

 

[Ol` Joe]

My question is this: If I was to shoot a close range shot, I would be over the max velocity for impact for this bullet.

Personally, I`d think the question should be is an extra 150 fps from a tube 2" shorter then the books max within the SAAMI pressure range for the cartridge............................?

 

[Antelope_Sniper]

Switch to the AccuBond. My dad shoots 60gr of 4831 behind 130bt out of a 26" tube. A couple years back he shot a Mule deer in the center of the chest, looking at him, from about 60 yards. It went down, then got back up. I don't think that would of happened with an AccuBond.

 

[JungleJim]

My question is this: If I was to shoot a close range shot, I would be over the max velocity for impact for this bullet.

Personally, I`d think the question should be is an extra 150 fps from a tube 2" shorter then the books max within the SAAMI pressure range for the cartridge............................?

Thats kind of what I was thinking when I read this. It sure would be interesting to know what kind of max pressure this load in this gun was on a Oehler 43 system.

 

[JD338]

I had actually wondered the same, that is why I referenced the load in RG #6. So long as it falls inside the guides loads AND there are no signs of pressure, it could be a "fast" barrel, lot of powder, or even the chronograph that was used.

JD338

 

[C.Smith]

Another vote for the accuabond, they advertise less fouling because of the type of jacketing, so I assume it should run through the barrel quicker yet.

I get over max book in with 165 Accubonds with my 3006 w/22" barrel. Made me scratch my head for a while, now I'm just plain happy with it.

Corey

 

[Antelope_Sniper]

Part of it Oldbrowning, is that H4831 is such a great powder for the .270 Win. In addition, the Remington brass provides you a little extra velocity over Win Brass. I've shot that same load behind 150gr bullets, but only with Winchester brass, and only in a modern turnbolt rifles. I think it was Elmer Kieth who used to shoot 62gr of H4831 behind a 130gr bullet. And of course, even he would only do it with Winchester brass.

 

[onlybrowning]

There are no signs of pressure at all with this load. I actually do not get much case length expansion, or flattened primers. It is no where near the gun's max. I have shot higher charges, 60 grains, 60.5 and it didn't show signs then either, other than starting to string shots.

I shot some 150 grain loads today, and the gun liked above the listed max load of H4350. I had very good results with 53.0 grains seated at a short OAL of 3.300." Pressure signs were not high with this round either. I tried seating them longer (3.340") and the group opened up.

 

[onlybrowning]

comparison of OAL. Same load otherwise.

 

[JD338]

onlybrowning

Nice shooting! The 53.0 grs w/ 3.300 OAL looks to be the load. Your C to C will be around .5", excellent.

Load up some more to verify consistent accuracy and you are set to go.

JD338

 

[FOTIS]

Nice shooting...You're good enjoy!

 

[JungleJim]

Looks perddy darn good to me.

 

[Greg Nolan]

The chrony will tell it all!! I found that Swift A-Frames are a different jacket (purer copper)and considered sticky. My one grain under max with 140 grain Swift A Frame was 3240 FPS. Wow. I called Swift and they said "well some rifles shoot faster than others" I cut back a grain and still get 3150 FPS.Good velocity but bad accuracy. I switched back to partitions and then accubonds. Normal velocity and WAY better accuracy.
Good luck
Elkhunt :grin: :grin:

 

[onlybrowning]

Can you guys believe that I have never used neck sized brass with this gun? It gets hard to chamber the cartridge after 2 or so neck sizes, and after all, it doesn't appear to need it anyway. This was brand new, never fired brass without uniforming the primer pockets, or deburring the flash holes. I usually include these steps, but didn't have time this time.

This rifle was a gift for my High School graduation and has been glass bedded and had some trigger work done.

 

[Big Squeeze]

The chrony will tell it all!! I found that Swift A-Frames are a different jacket (purer copper)and considered sticky. My one grain under max with 140 grain Swift A Frame was 3240 FPS. Wow. I called Swift and they said "well some rifles shoot faster than others" I cut back a grain and still get 3150 FPS.Good velocity but bad accuracy. I switched back to partitions and then accubonds. Normal velocity and WAY better accuracy.
Good luck
Elkhunt :grin: :grin:

.....................................YEP! Some rifles do shoot faster than others!..........I can certainly attest to that!.........150gr. @3155fps............180gr. @2994fps...........200gr.@ 2828fps.................All from a 16.5" barrel too; and verified by 2 chronys!............ :shock: :shock: :shock: :shock: