Tune loads off cold or hot bore?

[CanusLatransSnpr]

I was talking with a friend the other day about working up loads for varmint hunting, mainly coyote and ground hog, these shot primarily from a cold bore. I told him I would shoot a fouler shot and then a 3 shot group for load development. He then said that he thought that would not be too representative being that most shots taken would be from a cold bore, some times clean and some times not. Should I be doing my load development with shots taken from a cold bore? Letting the barrel cool down in between test shots or should I continue like I have been. Seems logical to tune from a cold bore being that most shots will be taken during the condition! Thanks!

Mike

 

[necchi]

In my experiance, with my guns. It seems each gun is it's own creature.

My 223 will shoot the first 3 back to back and make one hole, then it';s starts climbing, unless it's cooled. It needs 8-10 shots after cleaning to group.
The 7-08 will throw the first shot 4"s low, from a cold clean or fouled bore, then group all the rest sweet .
The 308 doesn't care, hot or cold, they all land in the same spot, it's not real fussy about bore condition but groups are a bit tighter when it's fouled.

Point is, with off the shelf hunters, there is no rule that fit's all. Ya kinda gotta find what your gun likes.
For a hunter, I like to leave'm fouled, and know where the first one goes. If it's not the same as the rest of the shot's ya need to find out why, or at least know what's going to happen.

 

[CanusLatransSnpr]

Necchi, I know what you mean by every rifle is its own creature and you have to take the time to figure it out. I tend to like to leave my barrel a "little" on the fouled side, anything over say 15 shots then it needs to cleaned and shot a little before I hunt with it again.

Lawrence, thanks for the info on determining if first shot is off from the rest. My problem is when testing a load, my fouler is shot at a different aiming point than where the group is shot as not to clutter where I'm shooting. Guess I need to take the time and try your process and see what my rifles behave like. By the way, I'm talking about tuning a load for maximum accuracy. After said load is determined, then go with the process above for first cold bore shot. That is if it isn't high volume shooting at prairie dogs or gophers like you mentioned.

Thanks again guys!

Mike

 

[K22]

When testing loads, I allow 5 minutes between each shot from varmint weight barrels. Also, I assess a loads capability based on a five shot group, retest another day to verify. All load testing is done off a benchrest with benchrest type front and rear support to give me the steadiest rest possible. During this phase, I don't touch the scope, I'm looking for group size only. Once I find a load I like, I sight in 1.5 inches high at 100 yards but this is only my preliminary sight it.

My final sight in is done off the shooting system I intend to hunt from. For me, it's shooting sticks. In my experinence, sighting in off a bench rest produces a different point of impact than off the shooting sticks so my final sight in for hunting is done off sticks. Once I get my shots centering at 1.5 inches high off the sticks at 100 yards; I'll shoot a few three shoot groups at 100 yards to verify zero, if my shots are centered within a 1.5 inch group, I don't adjust the scope any further. Again, I wait five minutes between shots. Most of my varmint rifle will hold 1/2 moa off the benchrest and on a good day I can hold a three shot group within 1 to 1.5 moa at 100 yards off the sticks.

I fire one fouling shot before load testing and sighting in when I have a clean barrel. Surprisingly, most of my rifles do not show a significant deviation from a clean barrel.

 

[CanusLatransSnpr]

K22, thanks for the info. Thats the kind of info I was looking for. My rifles have varmint weight barrels on them also so I would assume that this technique would work for me also. I appreciate the time and info!

Mike

 

[jonbearman]

Is your gun glass bedded? I just had one make me crazy,It was pillar bedded and discovered it moved in the stock,not alot but enough to make the first shot wild until it settled down.I have now glass bedded this rifle and cant wait to shoot it.I have had very few guns that shoot wild on the first shot but I have a couple that wont behave.It is frustrating to say the least.

 

[CanusLatransSnpr]

Jon, my Savage 22-250 VLP has been beeded with JB Weld and my Savage .243 that I put together sits in an HS stockwith an aluminum bedding block. The .243 shoots great. I wish I could say the same for the 22-250, its my problem child. Like I said, I was wondering if I should load test with a cold bore being that most of my shots are going to be taken from a cold bore? I need that cold bore shot to be accurate! Thanks!

Mike

 

[K22]

I wish I could say the same for the 22-250, its my problem child.

I had trouble with my 22 250's also, trouble being defined as obtaining consistant groups. At the recommendation of a fellow shooter, I tried IMR 4350. I was quite skeptical since I had never seen this powder recommended for the 22 250. However, I was shocked to find it group amazingly tight and consistant. I shot a several groups under 1/2 moa. The added advantage was there was a lot less case stretching than with Varget and H380. The load I used was 38.0 grains of IMR 4350 with 55 grain Nosler BT, Federal 210 match primers and Rem brass. This load is listed in the Nosler Manual, 5th edition so it's not something dreamed up on Pluto.

 

[CanusLatransSnpr]

K22, thanks for the input. Believe me when I say that I don't take any comfort in knowing that I'm not the only one that has had problems getting a 22-250 to shoot consistantly. I can see why you would be skeptical of the IMR 4350 since its burn rate is quite a bit slower than the powders that we normally use for this cartridge but, if it works then it can't be disputed. Thanks!

Mike