Pressure signs

[runtohunt]

I have a .280 AI that I have loaded with 62.5 g of RL 22 under a 145 grain Barnes LRX bullet with a Federal 215 match primer. I carefully worked up the load. It produced two 3/4" 4 shot groups without any signs of excess pressure. Or, at least it did until last Friday. During the initial load work the temps were 78-82 degrees in the "cool" morning air. Last Friday, I went out in the late afternoon and the temp was about 95 degrees. I shot a couple of shots. The first shot was ok. The second shot left an extractor mark. Out of the five shots three had extractor marks.
During my hunting season, I will not experience temps above 65-70 degrees if it gets that warm. Should I back the charge off or just not shoot it during the warm temps?? Any input would be greatly appreciated. Thank you

 

[FOTIS]

Yes. Higher temps will make the difference unless you keep your loaded rounds in a cool place.

 

[Ridgerunner665]

Reloder 22 is one of the worse powders for temp sensitivity...I know the stuff will shoot awesome, but it does get fussy in warm weather with upper level loads.

I've had to beat the bolt up with a plastic mallet numerous times because of it...

The load will most likely be fine if you save it for the cooler days...say less than 75 degrees.

 

[CatskillCrawler]

It seems like half the commercially loaded ammo I've shot recently has left extractor marks. The only types which haven't has been ammo for cartridges which there is a known concern with older rifles and their pressure capabilities.

As mentioned, try to avoid the heat.

 

[runtohunt]

Thanks guys. I am going to the range today. I am going to take some cartridges loaded down two gains at 60.5 and I will keep the rest of the cartridges (62.5 g) in a cooler and see what happens.

 

[runtohunt]

Headed out again today. Did not have any pressure signs with the 62.5 grain/145g LRX with the temp at 70 degrees. Decided to work on the 160 grain AB as well. Think that I might just stick with the AB. At 3.360" I was getting 3/4" group. 3.350" gave me a 1" group. 3.340" and 3.330" gave me just over 1.25" groups. No pressure signs. Darn those Nosler rifles can shoot.



Unfortunately, I have lost one of the rods to my Chrono so I do not know how fast the load is. As much as I like developing a load, I can't wait to start practicing at 200-400 yards

 

[DrMike]

Accuracy is pretty good, though. I'm certain the projectile is flying sufficiently fast to ensure a kill when it is put in the right place.

 

[Antelope_Sniper]

I would try some H4831. Not as temperature sensative, and will shoot just as well, if not better.