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Load development question

When you guys are doing load development do you shoot 3 or 5 shot groups... My problem is here in TX its 100 + and with 5 shot groups it takes forever for the barrel to cool and even a heavy barrel heats up after 4 or 5...

My last five shot string at 42gr of IMR 4064 and 168gr HPBT matchking hanged a perfect vertical string (.308) just a straight line up and down..God it was hot and I rushed it i am pretty sure, I am zeroing in on it but the barreling warming on shot 5 concerns me. I think 41.8 or 41.9 is gona be what iam looking for.. It just seems like I could get more data for my time ( group wise ) during this time of year with 3 shot groups...

I have been reading some post on not getting hung up on groups but iam not exactly sure what its all about yet.. Seems like a good group is a good group but then I read you don't want horizontal... The learning curve is never ending...

Thanks,
Shawn
 
If it is a hunting rifle 3 shots are plenty, I live in Texas also and live to hunt and can count on one hand the times I took more than two shots at anything. Shoot one shot and give it 5 to 8 min. to cool down then take another and so forth.
Terry Pohl
 
3 may get you in the ballpark but at least 5 to start dialing it in after you feel you're getting close. At least 10, or preferably 20 to confirm the load. You need a barrel cooler. I made this one and it works well, the barrel is ready to shoot in 60-90 seconds in 85-90 degree temp. This is a Coleman high volume low pressure air pump. It plugs into a vehicle power outlet or I just use a battery box that has the outlet built in. Connect it with a piece of good plastic hos
Blower.jpg
 
I forgot. A load that has worked for me is 41.7 grains of IMR4064 using the Hornady 168g BTHP or Sierra 168g M/K BTHP. This works very well for me in 60-75 degree temps. Seems not quite as accurate when it really heats up outside. Another more temperature stable load is 42.2g of Varget with either of the same bullets. I also jump mine .025".
 
Three shot groups are plenty for a hunting rifle, but not jut one three shot group, you need several that produces the same results.
Terry Pohl
 
3 may get you in the ballpark but at least 5 to start dialing it in after you feel you're getting close. At least 10, or preferably 20 to confirm the load. You need a barrel cooler. I made this one and it works well, the barrel is ready to shoot in 60-90 seconds in 85-90 degree temp. This is a Coleman high volume low pressure air pump. It plugs into a vehicle power outlet or I just use a battery box that has the outlet built in. Connect it with a piece of good plastic hos
Blower.jpg

I use this same setup and it does speed things up in Texas summers. When doing load workup, I like the barrel to go to ambient temperature for more dependable data. Even using the Extreme powders, you won't get your normal velocity/per degree results in 90-100* conditions. Try to shoot early in the day, until the weather normalizes in 3-4 months.
 
I use this same setup and it does speed things up in Texas summers. When doing load workup, I like the barrel to go to ambient temperature for more dependable data. Even using the Extreme powders, you won't get your normal velocity/per degree results in 90-100* conditions. Try to shoot early in the day, until the weather normalizes in 3-4 months.
Lol .. I do I got up when the sun came up yesterday to go shoot pistol and to test a shotgun I am playing with and by 9:50 I was soaking wet..

I got to hot during the bastrop complex fires to many times now I just can't do it anymore or it will put me in the hospital fast.. Not getting hot living in Texas is a hard thing to do. I have just been prepping brass for the last 3 weeks getting ready I guess for it to cool down in 3 months..
 
Maybe I could shoot multiple3 shot groups when I get dialed in better.. Its a. Savage 10 t tactical so its got a heavy barrel and I have enjoyed it very much so far.
 
In really hot weather (I hate the heat) I try to shoot early in the mornings or late in the evenings. I try to time it so about the time I'm finished, it's getting too dark to see. I have a 250' range across the street in a field. Here is what I use to haul gear and shoot from. The shade really helps keep me and the rifle cool. I can't use it if the wind is blowing much but usually on really hot days, the wind is dead calm. Too bad these aren't still available. I locked it upright and put in a tow bar, and a tote to haul everything in.
100_Shooting.jpg


SE40899.jpg
 
3-shot groups typically have a 4X to 5X spread in size. 5-shot ones a bit less. Their centers relative to point of aim have a smaller spread. Check the dozens of 5-shot groups shot at one range by each of the top ten people in a benchrest match.

http://azbrs.com/matches/2016-lv-hv-cactus-classic/

20-shot groups have about 1/10th times spread in size and several such group centers will be in a smaller area.

Shoot a 30-shot group plotting each 3-shot string's size and center distance from the center of the 30-shot group. Cheap and good way is to use 22 rimfire at 100 yards to see what happens.

If your shots start moving from point of aim as the barrel heats up, consider having the receiver face squared up with barrel tenon axis. Then the barrel tenon shoulder will have even contact all the way around instead of one point. Or develop the patience to let the barrel cool down between shots.
 
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In really hot weather (I hate the heat) I try to shoot early in the mornings or late in the evenings. I try to time it so about the time I'm finished, it's getting too dark to see. I have a 250' range across the street in a field. Here is what I use to haul gear and shoot from. The shade really helps keep me and the rifle cool. I can't use it if the wind is blowing much but usually on really hot days, the wind is dead calm. Too bad these aren't still available. I locked it upright and put in a tow bar, and a tote to haul everything in.
100_Shooting.jpg


SE40899.jpg
That's Awsome!!! with my heat problems and the fact I shoot 35 miles from my home I have considered loading my 8kw generator up and a big fan. But with it being 90 degrees at 8:45 am and only getting worse the heat waves are also getting to be a real problem.. Yesterday I went to shoot my carry pistol and a break open shotgun I have been working on for a snake charmer and by 9:45 am I was soaking wet..

After the bastrop complex fires I had to rebuild by myself and ended up having to get about 15 ivs for heat but had no choice since my family wasn't so keen on living in a box under a bridge so now my getting hot days are done.. Thats hard to do living in central Texas during this time of year..
 
3-shot groups typically have a 4X to 5X spread in size. 5-shot ones a bit less. Their centers relative to point of aim have a smaller spread. Check the dozens of 5-shot groups shot at one range by each of the top ten people in a benchrest match.

http://azbrs.com/matches/2016-lv-hv-cactus-classic/

20-shot groups have about 1/10th times spread in size and several such group centers will be in a smaller area.

Shoot a 30-shot group plotting each 3-shot string's size and center distance from the center of the 30-shot group. Cheap and good way is to use 22 rimfire at 100 yards to see what happens.

If your shots start moving from point of aim as the barrel heats up, consider having the receiver face squared up with barrel tenon axis. Then the barrel tenon shoulder will have even contact all the way around instead of one point. Or develop the patience to let the barrel cool down between shots.
Hey Thank you for replying.. The poi doesn't change I just don't like heating the barrel up and in this heat it can take forever to cool to the touch.. It takes about 3 or 4 hours to shoot five 5 round groups letting the barrel cool after each one.. Maybe I should just wait the 4 months.. Here its 90 degrees at 9am and its not even hot yet..
 
Heat doesn't hurt barrels.

Folks shooting NRA high power match rifles may shoot half the ammo ten shots per minute over the barrel's life. Their barrels last as long at those shot once per minute or slower. They've shot 1/3rd MOA 40-shot test group at 600 yards firing three to four times a minute.
 
Im in the same boat in TX, shooting in the shade is really all one can do. I bought one of those barrel cooler contraptions and Im not sure if it really makes any difference at all. I mean technically I see how its better but nothing is going to cool down fast when youre blowing 90 degree air through it. I leave 4-5 minutes in between each shot. I say if you dont want to leave your hand on the barrel for a few seconds its too hot to continue to shoot for load development.

Im actually considering skipping shooting this weekend just because its hot :eek:
 
Why not fix the cause?
Have the receiver face squared up.

Because that wont clear the swamp that develops in my ass crack.

And I dont notice any wandering or anything like that however I dont see how purposefully heating my barrel to uncomfortable levels could ever be a good thing despite what you claim. And for 10 shots I wouldnt worry about it but I shoot a lot more than 10. Well I dont notice any wandering that doesnt coincide with me getting pissed off from sweat running in my eyes.
 
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