Hazzardous Day at the Range

[Grumulkin]

I have this 22-250 that, while it shoots OK, didn't shoot quite as well as I though it should. I read that Jack O'Connor like IMR 4320 and, having never had or used that powder, decided to try it. With the current lack of components it took 2 or 3 months for me to find any but a couple of one pounders finally arrived on the shelf at Cabela's.



In particular, I haven't had much luck with lighter bullets in the 22-250 so decided to try some 52 grain Sierra BTHP MatchKings that came in cardboard boxes with metal reinforcements at the corners from back when 100 of them cost about $5.00. I also had some brand new primed Winchester brass from before the Sandy Hook scare.

Now here is where things got dicey. Even though some case mouths were dented I didn't (gasp) resize the cases at all! In addition to this, I didn't (double gasp) even chamfer the case mouths!

In concession to safety, I started low and worked up closeing my eyes at the first shot just in case. Until this group, none were worth talking about (probably because I was so worried about the unsized brass with dented mouths).



Another grain of powder with no scope adjustment and this is what I got. This happens frequently in load workup. At the lower end of the load range, groups start out large (probably because of fear of the gun blowing up). They then start to tighten up and POI (Point of Impact) may rise a little. Around the time that optimum and/or maximum safe pressure is acheived the is frequently a large change in POI and the groups frequently get larger again.

I probably won't push this load further as I don't think I would gain anything in accuracy.

I know that single 3 shot groups are of questionable significance but having two smallish 3 shot groups is reassuring. It will be 5 shot groups next and if they're also of the above sizes, I'll know I have a winner.

 

[WestKentucky]

Good shooting. And yeah, I think I would stop load development. My .270 did something similar. Started softball sized and tightened up to a nickel sized group at 100. It's 1.4" at 200 when locked up in a vice and shot with a hydraulic trigger. I did push further and the group fell apart quickly.

 

[Buck13]

They still make typewriter ribbons?!?

 

[blarby]

There's a guy here on THR named Ditchtiger.

He was the one who tought me that not everything in reloading needs to be surgically precise, new, shiney, and within tolerances I had arbitrarily set so high that no one could ever hit them in order to function.

Sometimes dents and dings are good enough.

There are things that matter, and things that don't.

Not every weapon made is a snipe-o-matic 6000, and not all of them can be made to shoot that way- and thats OK. Unless its a mosin, and its in his hands, then they are all sniper weapons.....

Miss that guy, we don't talk much anymore.

BUT the lessons will stick forever, and you just caught them too, of your own accord- remember that !

Those bullets are all kinds of minute-of-deer, and if you can steer them that well in the conditions you'll be using that 270 in, thats MORE than accurate enough for dinner !

 

[spitballer]

Interesting post, thanks for sharing your technique. I generally start with three-shot groups, too. The annoying variable for me is the fouling that inevitably occurs. My second and third groups are usually helped by fouling. Usually I'll alternate the different loads as the barrel warms up, to try to get a truer picture of what the different charges are actually doing.

 

[Grumulkin]

The weather has been a bit problematic around here. The days it hasn't been cold, raining or snowing, it has usually been very windy.



Here is a 5 shot group for further testing of what I believe to be the best load. I did make a scope adjustment since the previous targets were shot. The scope seems to be tracking well.



Here is the first target of today. Since the previous target was shot I adjusted up 1/4 MOA and left 1/4 MOA.



Now that I've worked up the load with cheap bullets, I decided to try some Barnes bullets. There was no scope adjustment since the previous target. If it had been a different cup and core bullet, chances are that the impact point probably would have been about the same. As frequently happens with Barnes bullets, the impact point is different though accuracy is about the same.

Notice a couple of things, though the Barnes bullets weigh 1 grain more than the Sierra bullets, I didn't change the load because the weight difference is insignificant. Also, in going from Sierra to Barnes bullets, I didn't change the load. There have been many times that I've worked up loads with cup and core bullets and then switched to copper monometal bullets with no change in other components; I've never had a problem of any kind with this practice.

There are two other things about the groups. They all show vertical stringing but are very consistent being about 1 inch high by less than 0.5 inches wide. I'm not sure of the reason for the vertical stringing. Those targets shot today, were shot 10 shots in a row without any barrel cool down. I don't think it's a problem with barrel warping or forend pressure. I also don't think it's a problem with scope parallax. I believe the most likely causes to be too hard a front bag or excess velocity extreme spread though I doubt the latter would show up at 100 yards.

When I get some more time, I'll try a different front bag and get the chronograph out.

 

[NCsmitty]

I've made comments on other posts about my success "back in the day" (70's) where I witnessed and shot 37gr of IMR4320 in several 22-250's in both M700 and M788 rifles using the old 55gr Power-Lokt bullets and I believe Remington primers, and all would group an inch or under.
These loads now exceed the maximum listed on the Hodgdon site, but the powder seems to be a good choice in that caliber. No chronograph back then, but it was flat shooting and seemed capable of decent velocity.
Good post on a forgotten powder.


NCsmitty

 

[oldeadeye]

Just a thought... whenever I see a string of shots that run vertically I think of a too warm barrel. In this "hurry up" world we live in, 5 minutes between shots seems an eternity... but watch those groups shrink when that occurs. Good shooting!

 

[bob4]

Just a thought... whenever I see a string of shots that run vertically I think of a too warm barrel. In this "hurry up" world we live in, 5 minutes between shots seems an eternity... but watch those groups shrink when that occurs. Good shooting!

+1 on letting the barrel cool.

 

[bainter1212]

Good post but....

I can't get past the typewriter thing. A lot of us here are old fashioned types but man! That is OLD fashioned indeed.

 

[cfoodeat]

Another +1 for the barrel heating up. My Remington 700 chambered in .270 does the same thing after 3 successive shots.

 

[LeonCarr]

I am gonna guess IBM Selectric .

With a high velocity cartridge like the .22-250 letting the barrel cool down between shots is a good thing both for your groups and your barrel life. A buddy destroyed the throat of his Heavy Barreled Savage .22-250 in about an hour shooting rapid fire at a prairie dog town in the Texas Panhandle.

Just my .02,
LeonCarr

 

[Grumulkin]

Maybe it is the barrel heating up and I'm going to test for that. The argument against it is that in a 10 shot string group sizes were essentially the same and in similar locations but I see where you are all coming from. If I can eliminate the vertical stringing, I see potential for consistent sub 0.5 MOA groups.

The typewriter is my treasured Brother WP-60 that I bought new around 1990. No one makes a similar typewriter any longer and it's quite handy for typeing out reloading labels and doing small jobs. It will get a new ribbon one of these days which may make better labels.

I use two products on my barrels that I believe have the potential to prolong barrel life. They are Prolix and Microlon Gun Juice. A few passes with Prolix after a shooting session and junk comes out; follow it with a dry patch and at the next shooting session there are no wild first shots. I use Microlon Gun Juice after deep cleaning and don't remove the residua with a dry patch; it also will not change group size (except for the better) or point of bullet impact unlike gun oil.

 

[Apex Predator]

I have found letting the barrel cool before the third shot improved the groups of high intensity overbore cartridges. Not much difference in 30-06 but in the 270WSM and 7 mag the difference is clearly visiable. If you have not tried H380 in the 22-250 you are missing out, I love that stuff. H380 and RL15 are the ONLY powders I use for it. Another thing I found out is at leased in the case of the BLR 22-250 I get considerably better accuracy slightly over max length 2.360" with my 55gr SGKs and 40gr V-Max.

 

[Grumulkin]

I've tried a bunch of powders for my 22-250 including Varget, H380, Winchester 760, IMR 4064, Superformance, IMR 8208 XBR and IMR 4895. I believe IMR 4320 is the best I've tried so far. I've never tried RL-15 in a 22-250 though it's my go to powder for several other cartridges.

I pretty much ignore book COALs and try to get my cup and core bullets near the lands. Barnes bullets are a bit different; I generally crimp them with a Lee Factory Crimp Die in the distal groove.

I've noticed a funny thing about barrel cooling. In the 22-250 for instance, after 3 or even 5 shots, the barrel isn't noticibly warm to touch. If barrel heat has anything to do with group size, it must have something to do with a change in the bore rather than the barrel warping. Also, in another gun I have, it takes a lot longer than 5 minutes to return to the so called "cool" state after shooting a 3 shot group.

 

[Crashbox]

Great to see someone else using IMR 4320. I have two kegs of it in stock, mainly for my .405 Winchester...

Although it seems that '4320 doesn't produce top velocities in a fair number of cartridges, it does have a habit of producing excellent groups in my opinion, YMMV.

I think '4320 is a very under-rated powder.

 

[GooseGestapo]

Sierra's "cheap" bullets ?????
In my world, it don't get any better than Sierra's.
My Rem 700ADL in .22-250 shoots 1-hole five-shot groups with Sierra's....50-55gr,you pick the style, it don't care.... 35.0gr IMR4320, 35.0gr RL15, 35.0gr IMR4064, or 39.0gr H380....Just don't seat them to over 2.350"oal.
And don't ask me why on that short of oal! It's just the way it is....

 

[Grumulkin]

Sierra's "cheap" bullets ?????
In my world, it don't get any better than Sierra's.

No disrespect of Sierra bullets; I think their match bullets are excellent but, mine were cheap at least by today's standards. It was a box I paid about $5 for years ago.

 

[41 Mag]

Another point on the barrel heating or cooling which was pointed out to me by an older fellow who shot a lot of BR at an old range I used to frequent.

When you shoot consecutive rounds while the upper portion of the barrel just ahead of the chamber is where most feel for heat, that same thing is also occurring directly opposite and under the barrel as well. The thing he pointed out was that the underside doesn't quite cool off as quickly being surrounded by the stock. While you might "feel" the upper side to be warm, the underside might be holding more heat, which could cause it to change the POI due to that.

To me it made sense, as my stringing was from low to high, which could easily be explained by the bottom of the barrel holding the heat longer than the top. This would cause the shift from low to high in POI. In my case I was shooting a 25-06 and running a very nice load of IMR-4831 under some 100gr bullets. Shooting at a rate of a shot per minute or so, the first three would be in a ragged hole, and usually the 4 shot would be just a touch high, followed by the 5 being about a 1/4" higher. Granted all 5 would still be right at or just under an inch, but if left to cool all 5 would be around or under 1/2".

The same rifle however, with RL-22, and the 115gr Partition will hold up to around 7 or so shots together in a ragged hole group, if fired about a minute or so apart, before they start to climb. Giving it ample time to cool of around 5 or more minutes between shots, I can easily keep them stacking into the same hole.

I have kept this in mind through the years and usually when I am working up loads I will have a couple of rifles out with me. One to work the load up with and the others to practice with while waiting for the barrel to cool. I shoot one round and set it aside, bolt open, and let it cool. Seems to work really well this way.

Just something to consider...