44 mag rifle vertical stringing

[T-Bird]

I have an H+R single shot 44 mag rifle that I have had for several years. I have used it for a close range deer gun, using mainly sub 44 mag level loads and taking advantage of the longer bbl to get adequate velocity for hunting. Doing this, I have also a very low recoil, low noise, effective deer rifle ideal for kids and people that don't really like recoil (me). Lately I decided to try heat it up a bit and get a little closer to 44 mag level loads so I could maybe stretch the range a bit. I found a lb of AA #7 in a pawn shop on sale for $21 which is CHEAP here. I loaded up some hi-tek coated 429421 sized .430 over 15.5 gr AA#7 and was able to get fairly consistent 11/4" to 11/2" round groups at 50 yds. The surprise came when I moved the target to 100 yds yesterday. I shot 5 shots at a 11/2' round circle from sandbags with the forearm rested on an adjustable Caldwell cradle (the same setup I always use) and got a 10" tall vertical string with the top hole right beside the spot. I don't see how that group could be "me", I have shot that setup alot with other guns and not had that result. I chronographed a similar load with 3 shots earlier (15gr) and got 2 in the 1480"s fps and 1 that was 1501fps. I added another 1/2 grain and it shot to the same POI at 50 and just as accurately, so I tried that one at 100 but didn't chrono it. I don't see how velocity variation could be responsible for this degree of stringing but maybe it is, I didn't chrono the 15.5gr load. Does anyone have any ideas I haven't considered?

[Wayne Smith]

First, shoot the same load but with the gun not touching the rest, just resting your hand on the rest. This will make a difference, especially with single shots and lever guns. Then report back.

[Rick Hodges]

If you shot round 1 1/2" groups and then suddenly 10"...I would check the scope and mounts first. Something is moving.

[T-Bird]

thank's Wayne, will do this PM.

[T-Bird]

the round groups were at 50 yds. The 10" 100 yd string was vertical, almost perfectly. Shouldn't I have gotten some stringing at 50 if it was the scope?

[Rick Hodges]

the round groups were at 50 yds. The 10" 100 yd string was vertical, almost perfectly. Shouldn't I have gotten some stringing at 50 if it was the scope?

It depends on when the scope/mount let loose. If it still is shooting 1 1/2" groups at 50....it isn't the scope. I thought you said the first group at 100 was 1.5" and then it started stringing.

[mdi]

How many bad strings did you get? I'd try at least once more, slow shooting to keep barrel heat low. There are a bunch of easy Handi-Rifle accuracy fixes that I found here http://www.go2gbo.com/forums/index.php Scroll down to the H&R section and there are several sub forums dedicated to the H&R rifles (the forearm attachment and pressure on the barrel are contributors to vertical stringing).

FWIW, I enjoy my Handi-rifle in 223 and 30-30 and some of the "tricks" I found on Grey Beard's forums have improved accuracy...

[T-Bird]

Yeah, I've got one in 223 as well. It shoots as well as I can. Used to have one in 25/06- tack driver with 100gr bullets (J word). Wish I hadn't sold it.

[kungfustyle]

Use all the same head stamped brass and weigh your bullets to within a grain variance. Make sure the brass is the same length different lengths different crimps, not so much difference at 50 but back it out to 100.... weigh each powder charge. Let the bbl cool between shots. Most handies don't like it hot. Eliminate all that you can.

[Dusty Bannister]

If your sighting system is secure, and you are shooting with the hands supported by the rest I have to ask if the cases are slightly sooted after firing your rounds. The reason I ask is that the Accurate Arms manual suggested starting load for the cast bullet you are using is 15.8 grains of Accurate #7. If your cases have been reloaded you might have lost the ability to seal the gases when you shoot.

Next, does the bullet actually mic .430" and what is the groove diameter of your barrel? There are a lot of things that could be slipping here but I would want to be sure you have a good seal to get a consistent powder burn. I am not into Hi-tek so would consider adding some soft wax bullet lube applied with the fingers to be sure that you are not having gas leak past the bullet if you are close to the groove measurement.

Since you are actually below the starting load, your bullet might be unstable and by chance the bullets are just dropping instead of shooting in a pattern instead of a group. Is the twist rate appropriate for the bullet length and velocity? Your chrono reading says you have enough velocity, but you may not have the RPM's. Dusty

[GhostHawk]

Have you tried putting an o-ring on the stud that takes the screw to hold the forearm on?

Try to support the rifle as close to the hinge point as possible. For starters take the forearm off and shoot 3 at 100. If you still get stringing its a load issue. If you get a tight group it is a forearm issue. Or possibly a barrel heating issue.

That should get you pointed in the right direction.

[Tatume]

Try again. If it still misbehaves, try another scope.

[T-Bird]

Tried again yesterday pm, same load with hand on rest. This reduced the string to 5" long for 5 shots. For fun, I brought along another load- 10gr AA#5 same boolit. This is a plinking load that I use in my pistols, runs about 950 fps from a 6" bbl. Shoots real straight in both of them. Anyway, I shot a 2" round group at 100 right after the string on the other load. I am using mixed headstamp, some Starline, some Winchester so I will eliminate that variable. I will remove the forearm too and try that. I may try to up the charge some. I'm not getting sooted cases, but I did with the #5 load that shot well. I guess the chamber in bigger in the Handi than the cylinders of my revolvers. I don't have a micrometer I only have a dial caliper and it says the boolits are .430. Thanks for all the help.

[OldBearHair]

Process: Check my dial caliper to zero. Measure with ball mike and micrometer then caliper. Same conclusion. I'm happy !

[mdi]

Another "try it"; remove the fore arm and rest the gun on the trigger guard. I did this to see if the forearm "pressure" had anything to do with the gun's accuracy...

[CIC]

44 mag handi rifles can be contrary. I worked a long time to find a solution. It took a very specific powder/bullet diameter to find success. Good luck in you efforts.

[Tatume]

It sounds like you are closing in on it. Keep up the good work.

[T-Bird]

Back yesterday-5 more shots. Upped the charge to 16.3 gr AA#7, all starline brass, tightened the crimp a bit, changed the boolit to a gc Thompson design since I'm upping the velocity. Hand held forearm, same 5" vertical string at 100. I just don't get how a round at 50, group goes to vertical at 100. May do the forearm removal thing today. I'm gonna shoot up this entire lb of cheap powder trying to find a good 100 yd load!:lol:

[mdi]

Back yesterday-5 more shots. Upped the charge to 16.3 gr AA#7, all starline brass, tightened the crimp a bit, changed the boolit to a gc Thompson design since I'm upping the velocity. Hand held forearm, same 5" vertical string at 100. I just don't get how a round at 50, group goes to vertical at 100. May do the forearm removal thing today. I'm gonna shoot up this entire lb of cheap powder trying to find a good 100 yd load!:lol:
That's the part I like the most, more reloading, trying different loads...

[T-Bird]

Back again yesterday, used same Thompson boolit, upped charge to 17gr- vertical but much worse. I shot the 12 gr AA #5 load with LY 429421 that I was "trying to improve upon" and got a nice 2" round group- all at 100. I don't think this gun likes AA#7!

[GhostHawk]

Listen to it!

[kenyerian]

Better slug your barrel.The SAAMI specs for 44 Magnum are different for pistols and rifles. The lands and grooves dimensions for a rifle, is 424" bore, .431" groove vs a revolver at .417" bore, .429" groove. My grandson's handi-rifle likes .432 sized boolits.

[waksupi]

I remember Felix stating that vertical stringing is too much powder, horizontal, too little.

[CIC]

Here is my recipe for success. .432 LBT cast and un-sized with a medium load of Universal. The bullet is plain base. One hole groups at 50 yards. Maybe that will be of some help. Oh by the way, I can get similar results from commercial cast if they are no smaller than .432.

[T-Bird]

Thanks for all the help! Went back today and shot the 15gr AA#7 load that I chronographed at 50, but never shot at 100. I got a 21/4 in total round group for 5 shots with 4 being within 1". This looks GOOD. Only load that hasn't strung vertically (Felix may have been right) it's below the starting load for 44 mag (15.8gr) but at about 1500fps, will serve my needs. Will try tomorrow for repeat results, if it works, I'll wait till it's colder and be sure it still shoots that well. During some of this testing, I shot some unsized boolits that were around .432, got the same stringing.Based on my mental math, this load should be in the upper 20K level, so it isn't too low pressure even tho it's below starting load. I could be wrong.

[T-Bird]

Went back today, placed the same target I used yesterday, holes and all at 100 yds. Shot 5 more, all of them were within yesterday's group. The rifle likes this load and so do I. The first load I shot at 100 only had 1/2 gr more pwdr and it exhibited vertical stringing. Amazing how much difference a small amt of pwder can make.Thanks everyone! This kind of stuff is what's both maddening and rewarding about this hobby!

[303Guy]

Have you considered the possibility of ignition inconsistency? Small differences could be affected by differences in muzzle lift due to barrel time and degree of lift, both acting together for that particular load.

I've had an otherwise accurate rifle producing strong vertical stringing with a particular powder. Horizontal spread was very slight.

[John Boy]

Vertical string group in all instances is not the fault of the rifle or the reloads. Give this article a read and see if any of the causes are yours, not the rifle or the reloads ... http://www.6mmbr.com/verticaltips.html

[T-Bird]

Read it John Boy thanks. I don't know. This isn't a bench rest gun, it's a 300$ H+R single shot. The trigger is hard, it's not well balanced, etc. I did however have good luck with another load using AA#5 and the same rest set up and bullet. I just wanted another, slightly hotter load to use at longer distance if the opportunity presented itself. My vertical string wasn't like the ones in that article. It was 10"! Not resting the forearm on the front rest and holding it in my hand,seemed to shrink the string to 5". When I got to 17gr, in my load "development", it was WORSE! When I backed off to 15gr, I got a nice, tight round 10 shot group. In my case, I think it WAS the load.

[303Guy]

It was the load but why? Interesting that reducing the load tightened up the group. This would indicate barrel harmonics. I was suspecting ignition and or burn variances which it could still be. I need to retest my rifle that gave me a 10 inch vertical string. Two rifles have done it to me actually. The first one I put down to action stress due to a misfit forearm. It was swollen after boiling to get all the oil out. Now it fits fine. The other gun was the load - different powder.

[T-Bird]

I don't know, I was looking for a load that was 15-1600fps from the rifle, which would be (I estimated) about maybe1250-1300fps from a 6" pistol.The AA#5 load that I was "improving" was a 1350fps load from a rifle, and is a real nice soft, accurate load for kids. I shot the 15 gr load over the chrono , 3 shots that were between 1481 fps and 1501 fps. It was a small sample size admittedly, but seemed to be consistant velocity at least. It also shot well at 50yds, but for some reason, I didn't shoot it at 100, I Increased the load to 15.5, and got stringing. Stringing didn't get worse till I got to 17gr. It was interesting that the only way inaccuracy was expressed was by vertical string. There was very little horizontal spread in any of the loads.

[T-Bird]

It's hard to believe that as thick as those H+R bbls are that they vibrate at all but I know they do.

[303Guy]

My No4 that gave bad vertical stringing has a can on it and normally shoots sub-MOA. The vertical stringing with BL-C(2) was astounding. Recoil increased a lot, as did muzzle blast. With H4350 the recoil with the can is like a 223. Followed by a push. I assume the push is caused by the gases escaping like a rocket engine.

[Mr_Sheesh]

Barrels vibrate a lot; Lean a car antenna against the barrel after checking zero, you'll find the shots change POI an obnoxious amount. Same thing for a tree branch etc.