My Brno Models 3 and 4 shoot well enough to hit 1700 or 1800 on an ARA unlimited target. Has anyone had actual personal experience improving the accuracy of these old rifles by pillar bedding them?
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707mike
Hey 707Mike.
Not by pillar bedding but I did put a light skim of bedding compound on a Brno Model 5 (ZKM573). Should have never sold that rifle. Ill replace it with same/similar some day.
Not by pillar bedding but I did put a light skim of bedding compound on a Brno Model 5 (ZKM573). Should have never sold that rifle. Ill replace it with same/similar some day.
This Rank Beginner has a notion the pillars will help reduce muzzle motion by reducing the amplitude of the vibration caused by ignition, if that makes any sense at all. =\
Sounds like you have already talked yourself into doing it.
Rock On
Im interested to see your results.
Rock On
Im interested to see your results.
First time back at the range after the Rank Amateur bedding job.
Trying now to set the tuner.
Trying now to set the tuner.
Attachments
Let’s keep in mind that pillars were developed for early fiberglass and thermo-set resin benchrest stocks that exhibited insufficient compressive strength. The stocks would crush when the action screws were torqued, so aluminum spacers/pillars were fitted precisely to the fiberglass reinforced plastic (FRP) stocks and BR receivers.
Someone then decided that, if pillars help benchrest shooters, they will make my wood-stocked CZ shoot even better, and “pillared” became a buzz word in the industry. (Yes, the Mauser 98 military rifles had steel inserts in the action screw holes in the stock, but that was to mitigate extreme compression of the oil-soaked wood in extremely severe combat conditions; the actions were not perched on top of the steel inserts)
The problem is pillars represent metal-on-metal point loading, a condition that, unless done perfectly, is more likely to create vibrations than full contact with the receiver in wood or in epoxy (the latter, by the way, I do recommend for rifles with demonstrably poor bedding).
One can determine the contact surface area in a given rifle by painting the lower half of the receiver with inletting black, carefully reinstalling the barreled action and torquing the action screws, then tapping the top of the receiver with a large plastic mallet. The contacting areas will be very obviously indicated by the black when the barreled action is removed and the bedding in the stock is inspected. If there is more or less even contact over most of the bedding area, the bedding is probably just fine. If the contact is inconsistent, or bearing on only one side, one end, or on one spot only, an epoxy bedding job is likely warranted, although scraping the black indicated areas, re-blackening the receiver, and repeating the process many times can often create very good bedding. It’s just easier for most to hog out all that evil wood and squish epoxy in there.
Regarding the pillars themselves, the underside of rifle receivers is almost always going to be an oddball radius, 1.20” diameter, for example, (the receiver bottom might be flat in some rifles) and there are no readily available ball-end mills that will cut an oddball radius on the top end of our pillars that will match the receiver contour. This means they have to be cut with a standard ball-end mill, like 1 1/8” or 1 ¼”, then fitted precisely to the contour of the underside of the receiver with abrasives. One might find a very large end mill very close in diameter to the receiver and cut the radius with it, but, again, a precise fit will likely require some hand fitting. Are you guys actually going to that length when installing pillars?
Yes, the gaps can be filled with epoxy, but then we no longer have that solid, metal-on-metal fit everyone wants, so one might as well just use epoxy bedding, which, as mentioned, absorbs vibrations better anyway. V-block-type pillars would probably be fine, but…
Let’s assume we do have pillar tops that perfectly match the receiver contour. Guess what? Those perfectly fitting aluminum pillars are epoxied into, yes, that unacceptably unstable wood! If wood stocks are as unstable and ever moving as we are led to believe, what happens to our perfectly fitting pillars when the wood expands, contacts, or otherwise moves? We’re back to pillars that have probably now moved enough with the wood of the stock to create true point loading, with possibly only one edge of the pillar in contact with the receiver. That is a recipe for inconsistency and vibrations.
I honestly do not think wood is nearly as unstable as we are led to believe, particularly by those who are pedaling synthetic stocks, so, in my view, if the pillars are reasonably well executed, they will do no harm, but I also don’t think they do any more good than a well-done epoxy bedding job, and even a good epoxy bedding job is often unnecessary. Again, if the bedding is poor, by all means epoxy bed your rifle, I just think the pillars are superfluous in wood stocks with good bedding, especially in sporters with already limited accuracy potential when compared with BR rifles. I know properly done pillars probably simplify torquing values, but that seems pretty minor to me.
Now, a stock carved when the blank is still wet can wreak havoc on a rifle. A student at our gunsmithing school made a very nice stock out of a highly figured but still-wet claro walnut blank. As I recall, it was a .458 on a Mauser 98, the .458 barrel having relatively thin walls. After inletting and shaping, he left the tightly screwed together barreled action and stock in his locker for a week when he went home for Christmas, or some other reason. When he got back, the forestock had warped with so much movement and energy, the barrel was actually bent.
Still, when wood stock blanks are properly dried and seasoned, there are few problems. I’ve made too many stocks with very tight inletting of the barreled action, bottom metal, and Niedner-style butt plates that, to this day, have not changed, to believe it’s a big problem.
The most common movement in wood stocks I’ve seen is the barrel channel housing a floated barrel moving to touch one side of the barrel. Not saying using a rifle in extremely humid conditions like Alaska won’t be a problem, but usually no issues for mere squirrel rifles.
Just my own personal experience.
Someone then decided that, if pillars help benchrest shooters, they will make my wood-stocked CZ shoot even better, and “pillared” became a buzz word in the industry. (Yes, the Mauser 98 military rifles had steel inserts in the action screw holes in the stock, but that was to mitigate extreme compression of the oil-soaked wood in extremely severe combat conditions; the actions were not perched on top of the steel inserts)
The problem is pillars represent metal-on-metal point loading, a condition that, unless done perfectly, is more likely to create vibrations than full contact with the receiver in wood or in epoxy (the latter, by the way, I do recommend for rifles with demonstrably poor bedding).
One can determine the contact surface area in a given rifle by painting the lower half of the receiver with inletting black, carefully reinstalling the barreled action and torquing the action screws, then tapping the top of the receiver with a large plastic mallet. The contacting areas will be very obviously indicated by the black when the barreled action is removed and the bedding in the stock is inspected. If there is more or less even contact over most of the bedding area, the bedding is probably just fine. If the contact is inconsistent, or bearing on only one side, one end, or on one spot only, an epoxy bedding job is likely warranted, although scraping the black indicated areas, re-blackening the receiver, and repeating the process many times can often create very good bedding. It’s just easier for most to hog out all that evil wood and squish epoxy in there.
Regarding the pillars themselves, the underside of rifle receivers is almost always going to be an oddball radius, 1.20” diameter, for example, (the receiver bottom might be flat in some rifles) and there are no readily available ball-end mills that will cut an oddball radius on the top end of our pillars that will match the receiver contour. This means they have to be cut with a standard ball-end mill, like 1 1/8” or 1 ¼”, then fitted precisely to the contour of the underside of the receiver with abrasives. One might find a very large end mill very close in diameter to the receiver and cut the radius with it, but, again, a precise fit will likely require some hand fitting. Are you guys actually going to that length when installing pillars?
Yes, the gaps can be filled with epoxy, but then we no longer have that solid, metal-on-metal fit everyone wants, so one might as well just use epoxy bedding, which, as mentioned, absorbs vibrations better anyway. V-block-type pillars would probably be fine, but…
Let’s assume we do have pillar tops that perfectly match the receiver contour. Guess what? Those perfectly fitting aluminum pillars are epoxied into, yes, that unacceptably unstable wood! If wood stocks are as unstable and ever moving as we are led to believe, what happens to our perfectly fitting pillars when the wood expands, contacts, or otherwise moves? We’re back to pillars that have probably now moved enough with the wood of the stock to create true point loading, with possibly only one edge of the pillar in contact with the receiver. That is a recipe for inconsistency and vibrations.
I honestly do not think wood is nearly as unstable as we are led to believe, particularly by those who are pedaling synthetic stocks, so, in my view, if the pillars are reasonably well executed, they will do no harm, but I also don’t think they do any more good than a well-done epoxy bedding job, and even a good epoxy bedding job is often unnecessary. Again, if the bedding is poor, by all means epoxy bed your rifle, I just think the pillars are superfluous in wood stocks with good bedding, especially in sporters with already limited accuracy potential when compared with BR rifles. I know properly done pillars probably simplify torquing values, but that seems pretty minor to me.
Now, a stock carved when the blank is still wet can wreak havoc on a rifle. A student at our gunsmithing school made a very nice stock out of a highly figured but still-wet claro walnut blank. As I recall, it was a .458 on a Mauser 98, the .458 barrel having relatively thin walls. After inletting and shaping, he left the tightly screwed together barreled action and stock in his locker for a week when he went home for Christmas, or some other reason. When he got back, the forestock had warped with so much movement and energy, the barrel was actually bent.
Still, when wood stock blanks are properly dried and seasoned, there are few problems. I’ve made too many stocks with very tight inletting of the barreled action, bottom metal, and Niedner-style butt plates that, to this day, have not changed, to believe it’s a big problem.
The most common movement in wood stocks I’ve seen is the barrel channel housing a floated barrel moving to touch one side of the barrel. Not saying using a rifle in extremely humid conditions like Alaska won’t be a problem, but usually no issues for mere squirrel rifles.
Just my own personal experience.
I will only add to above, in my limited experience, on my old used rifles (30-50 years old) the bedding is sometimes not good anymore. I can only explain it that over the decades of constant wood shrinking in winter time below zero with very little air moisture and expanding in summer time with high air moisture on a yearly basis has an effect. Of course the wood quality is also important. I have sofar never seen on a hunting rifle an oil soaked stock. But I regularly do a bedding job on the oldies. Usually in a way that is not seen to keep the old style look.
Again, I am all for epoxy bedding for rifles with poor bedding, new or old. It's the notion that pillars bestow some kind of magic to a rifle that I'm not buying. You do bring up a very good point, though, in that pillars in the bedding make a "freshening up" of an older rifle's bedding much more problematic.
Over the past two years a shooting buddy and I have ignored prices in our search for quality Brno Model 3 and model 4 target rifles. We have about eight of them between us. we thought they were very good target rifles until we started shooting ARA unlimited targets. The best of them is about like yours, "will hit 1700 or 1800 on an ARA unlimited target." I've spent the last two months prepping (including bedding) one of the Model 3s for today's local outdoor ARA Unlimited Match. Here are my scores: 1375, 1455, 1630, 1225. Conditions? 64º, 95% humidity, steady 1 mph right to left breeze, unlimited visibility. 'Nuff said?
Mike, if done correctly a bedding job (pillar or not) certainly shouldn't hurt how a rifle shoots. It probably won't make a rifle with already reasonably sound bedding shoot any better either.
The scores you're posting on the ARA UL target are about what I'd expect out a factory rifle like yours. It's a tough target for even custom RFBR guns. I'm not sure how much ARA UL you've shot at this point but also remember it takes some time to figure things out
The scores you're posting on the ARA UL target are about what I'd expect out a factory rifle like yours. It's a tough target for even custom RFBR guns. I'm not sure how much ARA UL you've shot at this point but also remember it takes some time to figure things out
I have wanted to shoot ARA locally for the last three years. It took quite bit of cautious encouragement to get the few local "target-head" rimfire shooters interested. At 83 years I'm a lot less energetic about getting such things going than I once was. Dawn Killough and our Rangemaster have been very supportive but the real break through was the appearance at our range of a younger member with an extensive background in firearms and a ton of energy, skills and abilities. He is now our Match Director. This week we held our third ARA sanctioned match. Five shooters, but a ton of enthusiasm and fun.
You are sure right, " it takes some time to figure things out". I am enjoying all of it a lot. Even the humbling part! =]
You are sure right, " it takes some time to figure things out". I am enjoying all of it a lot. Even the humbling part! =]
The only other thing I do to my rifles when I am not happy with precision after bedding is to do a recrowning job. Although as with all "precision enhancement" actions, no one can tell you the outcome. Sofar I have equal to better precision. With the later being typical. On informal target rifles I do the brass screw technique.
The target rifles haven't had a problem sofar because they shoot better than I do. But if in doubt I would go to my gun smith. Before recrowning he adjusts the barrel in the lathe depending on the bore axis NOT on the outer bore profil.
The target rifles haven't had a problem sofar because they shoot better than I do. But if in doubt I would go to my gun smith. Before recrowning he adjusts the barrel in the lathe depending on the bore axis NOT on the outer bore profil.
I agree with you that going to an experienced smith for proper crowning is best. But I have purchased brass .22 crowning bits and not yet used them. I'm told to use 600 grit paste on a bit chucked up in a hand drill, but that seems informal at best. I do not know what the "brass screw technique" is. Would you mind telling me?
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