Home Forums Reloading Big Game Rifles Load too hot?

It is a 260 rem tikka action with custom shilen barrel. The load is 45 grains H4350 with 120gr Hornady gmx at .030 off. It gives a sticky case every once in a while with norma cases. I tried some Lapua cases and fired a group. The first time was fine but the second time on one shot the primer leaked. How could this load be too hot at 1.5 grains from max?

Reloading data is a guide, not the absolute that some think it is.
Case volume can and does vary between brands. Bullets can also vary the top end of the loads. So can rifles. Factory rifles for instance, can be have oversized bores or longer/shorter throats. All of which can affect where the top end is for your handloads.
The only way to tell is to clock the loads. When you reach factory velocity, with the best performing powder(s) you should be pretty close to the design pressure level for that cartriage. E

I got a call from one of my shooting buddies who was having the same problem, except those that stuck chambered a little too hard.

He took a magic marker and coated the end of the neck on those cases that had stuck. When he removed them from the chamber, the marker was worn off. This was a 20 Practical that measured 1.750, the same as the specs. There was a problem with the reamer as there should have cut .010 deeper. So, he is going to have to cut his cases back .005-.010.

Never seen this problem before. By the way, the cases that did not stick, were shorter than the 1.750 in length.

Winchester primers?

Yes winchester

There has been a lot of talk here lately about unplated Winchester primers leaking at normal pressures, maybe a metalurgical problem. Look at the Primer Question For Mule Deer thread in the Ask the Gunwriters subforum.

I've read of problem Winchester primers. I have 3000 and need to contact Winchester about which lot #'s are involved.

Do you have a chronograph? If the speed you are getting is at or above a the speed shown at a max load, then you are at or above a max load in that rifle/load combo.

I've only ran into that issue once before. The load manual showed 3050 fps with 66gr as a max load. I chronographed 3100 fps at 65 gr and got sticky bolt lift. I backed off to 63.5 gr and all was well.

It was shooting 2950. The hodgdon load at 46.5 is 2960. Will a 1-8 twist build more pressure than a 1-9 twist?

No....but a tight custom barrel, a mono bullet with a lot of bearing surface,and a near max load ,might.

Over length cases can cause pressure spikes too. If you aren't trimming, or at least checking the length of cases after each sizing you can get one that's a little long, which tends to crimp a case, and pressure spikes.

You can absolutely get into over-pressure with well below suggested max loads. I have two .30-06 rifles, one an old 700 with a 26" Douglas barrel, and one a stainless factory Weatherby Vangaurd 24". Both are very accurate and shoot 150 sst or 155 Scenar to almost the same poi. The 700 likes IMR 4064 and starts showing undue pressure at 49 grains. The Vanguard likes IMR 4350 loaded at 56 grains and shows pressure signs in hot weather. Winter velocity is in the mid 28s and in summer jumps over 2900. My son and a friend each have .30-06s that using these loads they limp down to the target at much slower velocity. We are not guessing. We shoot them through a chrony. If we used some of the loads suggested here in the .30-06 loads it would take a pipe wrench to open the action.

Update and lesson learned. The man was right about the tight custom barrel and monometal bullet. Got the load worked to 43.5 of H4350 at 2920. No sticky bolt and pressure signs. Thanks for your input.