Group size versus ammo

geetarman · November 8, 2014, 02:52 PM

Just for the fun of it, I took the Anschutz MPR64 to the range yesterday to look at the difference in performance of three grades of Lapua ammo.

Each group is 5 shots at 50 yards. I am blown away at the difference. I also shoot a couple of other bolt guns. A CZ452 Trainer and a Ruger 77-22. They will shoot very similar groups as the Lapua Standard with anything I put through them. Both of this rifles have shorter barrels while the Annie is HUGE. I would not have thought the Annie would be so ammo sensitive yet the pictures don't lie.

I shot Lapua Standard, Lapua CenterX, and Lapua Midas. I have also shot Eley Tenex in this rifle and the Annie does not like that very much either. Take a look at the pictures and see for yourself. First pic is Lapua Midas. Second is Lapua Center X and the last is Lapua Standard.

The order of shooting was Standard, then Center X and then Midas.

Bart B. · November 8, 2014, 08:23 PM

I'd shoot 20-shot groups with each. There's a 70% chance the loads producing those largest groups will also shoot 5 into a small one like the Center X one. 5-shot groups have a 30% chance of showing what 20 to 30 would go into.

I'm more curious why the two big groups were that big. Having shot all sorts of rimfire in Anschutz medium quality barrels such as your 64; all put 20 shots inside an inch at 50 yards.

Is the barrel totally free floated? Stock screws torqued to about 25 in-lbs? Barrel squeaky clean?

geetarman · November 9, 2014, 06:34 AM

Bart ,

No doubt 20 shot groups would be more informative. I normally only shoot five shot groups. I have shot five shot groups on a standard 6 bulls eye target and then stapled another 6 bulls eye target on top of the first and shot another set of five shot groups. I stapled another 6 bulls eye target and did another series of five shot groups. when I took the targets down, the first one had 15 holes and the second one had 10 holes and the third and last one had 5 holes per bulls eye. Group size is slightly enlarged as you can imagine but the pattern is similar in that the rifle likes the Center X ammo best.

This might be heresy to competition shooters, but I do NOT clean any of my 22 LR rifles. Other than getting the preservative oil out of the barrel before shooting it the first time, I have not done anything to the barrel.

I will check the tension on the bedding screws. I do not have anything to measure the torque yet. That is something that would be of benefit.

Yes the barrel is completely free of the stock. There is plenty of gap around it.

Bart B. · November 9, 2014, 09:31 AM

I've no issues with folks who don't clean their 22 rimfire barrels. We all get to choose what accuracy level is acceptable, what resources to expend getting it and whether or not to do what's done to barrels producing the best.

It's the same thing with 22 rimfire barrel life. Never wearing out versus 20K to 30K rounds. And what the criteria is to determine it.

I've tested 1 poor, 2 average and 2 high quality .22 rimfire barrels for accuracy without cleaning. . . .

The poor one's best accuracy was about 1.5 MOA at 50 yards for about 75 rounds, then it had opened up to over 2 MOA and a hundred or more later, 2.5 MOA and stayed there for a couple hundred rounds. After I cleaned it, it went back to about where it started then got worse again.

Those average ones were much the same starting out at about 1 MOA, then opening up to almost 2 MOA where it stayed until cleaning.

High quality ones were no different except they started out at 1/2 MOA, then opened up to about 3/4 minute then only up to 1 MOA.

Others I've discussed this with had similar results. After the first few hundred shots, .22 rimfire accuracy degraded where it stays for a while. As the barrel throat erodes more, accuracy slowly gets worse as bullets are deformed more and they're more unbalanced. If one does not observe this happening, so be it.

geetarman · November 10, 2014, 11:39 AM

Bart,

Have you ever observed significant changes in performance lot to lot of better rimfire ammo? The gunsmith at Rio Salado, where I get my rimfire ammo says the Lapua Standard, depending on the lot, will perform as good as the Center X. He says the same thing happens with different lots of Center X as well as Lapua Midas.

I am going to check the action screws on the rifle today.

It is not my intention to pursue the last iota of accuracy out of my rifle. I am just too old to sweat it any more. I would like to get a better handle on the variation I am seeing with Lapua ammo in general.

From what I see, the Midas as well as Eley Tenex are not very good in the rifle I have although they shoot fine in the CZ and Ruger.

In YOUR opinion, who manufacturers the best rimfire ammo? Do you have a brand that you REALLY like?

I have duplicated the Lapua Center X target group that I posted at 100 yards. It was DEAD calm at the range, but I have to tell you the rifle impressed me when it did that.

The rifle is far more accurate than I am behind the trigger. I really wish I could have owned a rifle like that when I was 25 or so.

Bart B. · November 10, 2014, 02:46 PM

All 22 rimfire ammo lots of a given make and type will have a different accuracy level in a given rifle. The three best makes (Eley, RWS and Lapua) with one muzzle velocity will typically shoot best in a given rifle. Eley Tenex can be ordered by velocity:

http://www.killoughshootingsports.co...mmunition.html

Find out what velocity of Tenex your rifle shoots best then pick the lot closest to it. It's all based on where the bullet leaves the muzzle on the muzzle axis vertical whip cycle.

My Anschutz 1911, both the current barrel and first one, shot a couple lots of Eley Tenex and RWS R50 & R100 with the same best accuracy. But neither as accurate as the last of an old late 1980's lot of Eley Tenex I almost set a record with a few years ago. Most of the smallbore records shot at 100 yards before the early 1980's still stand. Ammo's never been that good since.

geetarman · November 14, 2014, 07:26 PM

Bart,

So I cleaned the barrel and checked the stock mounting screws. They were not loose but they were not as tight as they should have been. The manual says to torque the screws to 44 in/lbs and that seems awfully tight. I torqued them to 30. Because the manual was not particularly clear, I also torqued the trigger guard screw and promptly stripped it. I think it just screws in to a not that is inletted to the stock. I will check when I take the gun down again. I want to fix it but I don't want to take the gun out of the stock just yet.

I shot 5 sighters with Lapua Standard to get the scope pretty close. I was shooting at 50 yards. The gun came around after the 10 round and I started shooting the usual 6 target set up in the same order I have been. The rifle shows a distinct preference for the Lapua Center X and the same can be said for the Wolf Target. The Midas shot better as did the Tenex but none really came close to the Lapua Center X and the Wolf.

I have read on one of the rimfire forums that others have stripped the trigger guard screw as I did and have just removed it. I am not sure how important it is.

I am concerned about torqueing the front and rear stock screws to 45 in/lbs.

It just seems really excessive. If that gets buggered, I would be looking at some welding/brazing on the barreled action and I am not anxious to do that.

I would appreciate your advice or any tips you might have.

Thanks!

Bart B. · November 14, 2014, 07:59 PM

I think any 22 rimfire stock screw torqued over 30 in-lbs is too much. Especially for receivers with smaller diameters.

November 9, 2014, 06:34 AM	#3
geetarman Senior Member Join Date: November 18, 2009 Location: Arizona Posts: 3,157	Bart , No doubt 20 shot groups would be more informative. I normally only shoot five shot groups. I have shot five shot groups on a standard 6 bulls eye target and then stapled another 6 bulls eye target on top of the first and shot another set of five shot groups. I stapled another 6 bulls eye target and did another series of five shot groups. when I took the targets down, the first one had 15 holes and the second one had 10 holes and the third and last one had 5 holes per bulls eye. Group size is slightly enlarged as you can imagine but the pattern is similar in that the rifle likes the Center X ammo best. This might be heresy to competition shooters, but I do NOT clean any of my 22 LR rifles. Other than getting the preservative oil out of the barrel before shooting it the first time, I have not done anything to the barrel. I will check the tension on the bedding screws. I do not have anything to measure the torque yet. That is something that would be of benefit. Yes the barrel is completely free of the stock. There is plenty of gap around it. __________________ Geetarman Carpe Cerveza

November 9, 2014, 09:31 AM	#4
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	I've no issues with folks who don't clean their 22 rimfire barrels. We all get to choose what accuracy level is acceptable, what resources to expend getting it and whether or not to do what's done to barrels producing the best. It's the same thing with 22 rimfire barrel life. Never wearing out versus 20K to 30K rounds. And what the criteria is to determine it. I've tested 1 poor, 2 average and 2 high quality .22 rimfire barrels for accuracy without cleaning. . . . The poor one's best accuracy was about 1.5 MOA at 50 yards for about 75 rounds, then it had opened up to over 2 MOA and a hundred or more later, 2.5 MOA and stayed there for a couple hundred rounds. After I cleaned it, it went back to about where it started then got worse again. Those average ones were much the same starting out at about 1 MOA, then opening up to almost 2 MOA where it stayed until cleaning. High quality ones were no different except they started out at 1/2 MOA, then opened up to about 3/4 minute then only up to 1 MOA. Others I've discussed this with had similar results. After the first few hundred shots, .22 rimfire accuracy degraded where it stays for a while. As the barrel throat erodes more, accuracy slowly gets worse as bullets are deformed more and they're more unbalanced. If one does not observe this happening, so be it. Last edited by Bart B.; November 9, 2014 at 02:39 PM.

November 10, 2014, 11:39 AM	#5
geetarman Senior Member Join Date: November 18, 2009 Location: Arizona Posts: 3,157	Bart, Have you ever observed significant changes in performance lot to lot of better rimfire ammo? The gunsmith at Rio Salado, where I get my rimfire ammo says the Lapua Standard, depending on the lot, will perform as good as the Center X. He says the same thing happens with different lots of Center X as well as Lapua Midas. I am going to check the action screws on the rifle today. It is not my intention to pursue the last iota of accuracy out of my rifle. I am just too old to sweat it any more. I would like to get a better handle on the variation I am seeing with Lapua ammo in general. From what I see, the Midas as well as Eley Tenex are not very good in the rifle I have although they shoot fine in the CZ and Ruger. In YOUR opinion, who manufacturers the best rimfire ammo? Do you have a brand that you REALLY like? I have duplicated the Lapua Center X target group that I posted at 100 yards. It was DEAD calm at the range, but I have to tell you the rifle impressed me when it did that. The rifle is far more accurate than I am behind the trigger. I really wish I could have owned a rifle like that when I was 25 or so. __________________ Geetarman Carpe Cerveza

November 10, 2014, 02:46 PM	#6
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	All 22 rimfire ammo lots of a given make and type will have a different accuracy level in a given rifle. The three best makes (Eley, RWS and Lapua) with one muzzle velocity will typically shoot best in a given rifle. Eley Tenex can be ordered by velocity: http://www.killoughshootingsports.co...mmunition.html Find out what velocity of Tenex your rifle shoots best then pick the lot closest to it. It's all based on where the bullet leaves the muzzle on the muzzle axis vertical whip cycle. My Anschutz 1911, both the current barrel and first one, shot a couple lots of Eley Tenex and RWS R50 & R100 with the same best accuracy. But neither as accurate as the last of an old late 1980's lot of Eley Tenex I almost set a record with a few years ago. Most of the smallbore records shot at 100 yards before the early 1980's still stand. Ammo's never been that good since. Last edited by Bart B.; November 10, 2014 at 03:55 PM.

November 14, 2014, 07:26 PM	#7
geetarman Senior Member Join Date: November 18, 2009 Location: Arizona Posts: 3,157	Bart, So I cleaned the barrel and checked the stock mounting screws. They were not loose but they were not as tight as they should have been. The manual says to torque the screws to 44 in/lbs and that seems awfully tight. I torqued them to 30. Because the manual was not particularly clear, I also torqued the trigger guard screw and promptly stripped it. I think it just screws in to a not that is inletted to the stock. I will check when I take the gun down again. I want to fix it but I don't want to take the gun out of the stock just yet. I shot 5 sighters with Lapua Standard to get the scope pretty close. I was shooting at 50 yards. The gun came around after the 10 round and I started shooting the usual 6 target set up in the same order I have been. The rifle shows a distinct preference for the Lapua Center X and the same can be said for the Wolf Target. The Midas shot better as did the Tenex but none really came close to the Lapua Center X and the Wolf. I have read on one of the rimfire forums that others have stripped the trigger guard screw as I did and have just removed it. I am not sure how important it is. I am concerned about torqueing the front and rear stock screws to 45 in/lbs. It just seems really excessive. If that gets buggered, I would be looking at some welding/brazing on the barreled action and I am not anxious to do that. I would appreciate your advice or any tips you might have. Thanks! __________________ Geetarman Carpe Cerveza Last edited by geetarman; November 14, 2014 at 07:35 PM.

November 8, 2014, 08:23 PM	#2
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	I'd shoot 20-shot groups with each. There's a 70% chance the loads producing those largest groups will also shoot 5 into a small one like the Center X one. 5-shot groups have a 30% chance of showing what 20 to 30 would go into. I'm more curious why the two big groups were that big. Having shot all sorts of rimfire in Anschutz medium quality barrels such as your 64; all put 20 shots inside an inch at 50 yards. Is the barrel totally free floated? Stock screws torqued to about 25 in-lbs? Barrel squeaky clean?

November 14, 2014, 07:59 PM	#8
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	I think any 22 rimfire stock screw torqued over 30 in-lbs is too much. Especially for receivers with smaller diameters.