Barrel temp ?

clay_fv

clay_fv

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I've only worked on precision with ARs in heavy barrels. I recently bought a Benelli Lupo which SHOULD be super accurate. I just started loading for it, but I'm starting to wonder how much I should be letting the barrel cool between groups. I've managed to get one round into sub MOA, but the second time through it turns to junk. I'll typically shoot 3 or 4 five round groups, all different loadings (as in everything the same except powder charge). Then I go get my target, change it out (100y), then get back to it. Let's say each shot is about 45 seconds apart. That's a guesstimate. I load each one, one at a time. (As in I don't keep anything in the magazine.) Take my time, breathe, etc, then fire. Nothing is rapid fire.

My initial thought is that my barrel is heating up a lot quicker than my ARs that had much heavier barrels. Maybe I need to wait a lot longer? I'm looking to repeat my successes, but when I shoot one group (of the same loading) at .6MOA, then the next is 1.5, it confuses the hell out of me. Is this simply an issue of the barrel getting hot? When I say "hot", I touch the barrel and say, "Yeah that's nice and warm". It's never an "ouch!" moment.
 
Have you re-checked all the screws are torqued properly, including scope, base, stock, etc?
Have you made sure the barrel is free floating as designed and there's not something touching?

From a quick glance, the Lupo is a relatively lightweight Sporter configuration. But, the barrel is free floating and has been cryo'd.

Does it group well every first group?
 
Are you doing ladder tests or looking for a node? Caliber, bullet, powder?

I've never shot one but it appears to me that these are relatively light hunting rifles with a No. 1 or 2 barrel. If it groups 1 moa or less (consistently) sometimes that's the best you can expect. Wait two minutes between shots or shoot three times and let it cool a bit longer.

Is this a hunting rig?
 
If your first group or two is good and groups 3 and beyond are worse, it's probably the barrel heat. A sporter barrel can get warm in under 10 rounds if shot quick enough.

Next time shoot 2 groups, remove the bolt and let it cool for a good 15 minutes. Shoot 1 more group and check the results. If all 3 groups are good, especially the 1st and 3rd, your barrel is probably getting too warm. For extra confirmation, shoot 4-5 more groups and see how much the groups open. There's always a chance the rifle might prefer a very clean barrel, it's hard to say for sure.
 
I've seen these at the club but never tried one:

www.midwayusa.com

MagnetoSpeed RifleKuhl Barrel Cooler

Tired of waiting and waiting for your rifle to cool down? MagnetoSpeed's new barrel cooler, RifleKuhl, is designed to get barrel temperatures down to...
www.midwayusa.com www.midwayusa.com
 
Amazon has small air pumps for under $20 that are USB rechargeable. They come with various size hose adapters. Simply purchase a piece of rubber hose to fit into your action and you are good to go. For the price of the Midway product you can purchase and assemble three.
 
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Thanks for the replies. I have a feeling I'm just heating the thing up. Man do I hate waiting forever! I was going to actually ask about using a small fan!
 
Oh, I want this to simply be a HIGHLY accurate hunting rifle. I want to be able to target shoot and also hunt with it. Right now my first rounds have been with Sierra 168gr TMK behind 8208 and Varget with new Alpha brass, CCI 200 primers. I shot some factory 178gr ELDX just to see what a factory load would do and it was right around 1MOA.
 
What caliber is it??
 
I'm assuming its in 308? Get a barrel cooler and something to check the temp of the barrel. I use these strips glued to my competition rig.


Amazon product ASIN B01FVOQL84


, I like my Riflekuhl but any of the usb type fans will work. use the strips and the cooler to make sure each shot is at the same temp range. If all you're wanting is a highly accurate hunting rig then I would only worry about the first round impacts. I would completely cool the gun each time. This will take some time so bring another gun to shoot while waiting.
 
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Zbizzle911 said:
I'm assuming its in 308? Get a barrel cooler and something to check the temp of the barrel. I use these strips glued to my competition rig.


Amazon product ASIN B01FVOQL84


, I like my Riflekuhl but any of the usb type fans will work. use the strips and the cooler to make sure each shot is at the same temp range. If all you're wanting is a highly accurate hunting rig then I would only worry about the first round impacts. I would completely cool the gun each time. This will take some time so bring another gun to shoot while waiting.
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Yes, 308. Your media insert didn't come through. I definitely can see a benefit to something like a thermal temp gun. Hadn't thought of that. I had one years ago for checking tire temp when I was racing. Hellifiknow where it went. LOL. Not like they're expensive. I could easily grab one when I order a small fan.
 
clay_fv said:
Would you need a bedded action if the barrel is free floating?
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Yes. That is to say, action screw torque can affect accuracy and POI, and in my experience, more so on round, 2-screw actions as opposed to 4-screw squared receivers. This applies bedded or otherwise. Difference being that without bedding, temperature swings be it via ambient temps or heat soak from the barrel can have more of an impact on action torque than a rifle that has been bedded. Whether its going to move your particular gun close to a full MOA at 100 yards, I don't know, but there can be a cumulative affect along with barrel temps. We used to see significant performance impact on wood stocked .22 match rifles that weren't bedded, and when experimenting in action screw torque values, even minute changes would impact group sizes (both with or without bedding).
 
clay_fv said:
Yes, 308. Your media insert didn't come through. I definitely can see a benefit to something like a thermal temp gun. Hadn't thought of that. I had one years ago for checking tire temp when I was racing. Hellifiknow where it went. LOL. Not like they're expensive. I could easily grab one when I order a small fan.
Click to expand...
Temp tape
 
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Zbizzle911 said:
Temp tape
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Thanks. I just got a decent temp gun and the riflekuhl. Going to try it out tomorrow. I just got some 175gr Sierra TMKs in and trying Sierra's listed accuracy load with TAC.

As a side note, I use a Forester micro seater die and I've never had a bullet that seated perfectly every time with this die. Every single one seated within 1 thousandths of the others. The 168s always had a tiny amount of "stick" and they'd be off by up to a half a hundredth. Looking forward to trying these out. I also got some 155gr ELDMs to try at the other end of the weight spectrum, but Sierra's manual just has such better load data for each of their bullets whereas Hornady's is generic.
 
clay_fv said:
Thanks. I just got a decent temp gun and the riflekuhl. Going to try it out tomorrow. I just got some 175gr Sierra TMKs in and trying Sierra's listed accuracy load with TAC.

As a side note, I use a Forester micro seater die and I've never had a bullet that seated perfectly every time with this die. Every single one seated within 1 thousandths of the others. The 168s always had a tiny amount of "stick" and they'd be off by up to a half a hundredth. Looking forward to trying these out. I also got some 155gr ELDMs to try at the other end of the weight spectrum, but Sierra's manual just has such better load data for each of their bullets whereas Hornady's is generic.
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Whats your process? Do you expand with a mandrel? Whats your neck tension? Do you anneal? I really like the Short Action Customs seater die and comparator kit. I never have over .0005 variance with it.
 
Zbizzle911 said:
Whats your process? Do you expand with a mandrel? Whats your neck tension? Do you anneal? I really like the Short Action Customs seater die and comparator kit. I never have over .0005 variance with it.
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These are all brand new Alpha brass. No annealing yet. Hopefully in the future but I also have 350 more pieces of new brass to work with. I understand I can go three reloads before I need to anneal.

I use the full resize, carbide Redding premium die. However, I've yet to resize it or reuse any brass for this rifle. This brass is only being used with this rifle. I tried to make my AR10 308 highly accurate, but it beat the hell out of my brass. I've given up on that platform for that purpose and moving on to this bolt action. I still love my AR10s but just don't think they're as realistic for 1000y, repeatedly.

I'm "kinda" new to reloading for precision. (Been reloading for over 10 years but not for high precision.) Learning so much, but have more to learn. I just want a functional rifle that I can comfortably shoot 1000y with. Might not need to, but I want the ability. I don't want a highly custom rig that I'd go slogging through the woods with. I just want to know that when I adjust for whatever environmental variables exist, I hit my target. Lofty goal, but that's my goal. Before I proceed with that goal, I have to have a very consistent sub-moa load, preferably 1/2 moa.
 
For hunting loads I'd set my neck tension at .004. So I'd get a .304 Sinclair TIN coated mandrel in one of their expander dies. They're cheap. Use the mandrel to set the neck tension and then prime and load. It doesn't get any better than Alpha brass. In my competition gun I run .002 neck tension and set it with the tools listed above. For hunting you want a .001-.002 more than that so you don't run into bullet setback. When you go to size your brass only bump the shoulder back .002 , use a comparator to measure this.
 
Zbizzle911 said:
For hunting loads I'd set my neck tension at .004. So I'd get a .304 Sinclair TIN coated mandrel in one of their expander dies. They're cheap. Use the mandrel to set the neck tension and then prime and load. It doesn't get any better than Alpha brass. In my competition gun I run .002 neck tension and set it with the tools listed above. For hunting you want a .001-.002 more than that so you don't run into bullet setback. When you go to size your brass only bump the shoulder back .002 , use a comparator to measure this.
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Thanks, and I'll be asking more questions as time goes. I do have a comparator and have been bumping .004 for my AR-10. But I know I don't have to as much for a bolt action. I've got thousands of pieces of brass for those rifles (I have 3 different '10s), but this Alpha brass is solely for this rifle.
 
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