SD and Barrel Harmonics

Larry Elliott said:
Back when I could see worth a hoot I tried ladder load development, but it made my head hurt - BAD. Since then I've listened to people who I could see shot well, and/or who built rifles that shot well. Now when I work up a load I tend to tip the powder cannister up until I get the velocity I want, or change powders until I do. Then I fiddle and jiggle things around like seating depth until I get the accuracy that I'm looking for. It's pretty seat of the pants, but seems to work.

One thing that a local gunsmith who puts together some pretty accurate rifles told me when I was trying to get one rifle to shoot like I thought it should was that barrels with sharply angled leades tend to not like bullets seated up close to the rifling, while those with shallow leades tend to like bullets at or into the rifling. Many factory rifles, and I'm sure older custom rifles likely have fairly sharp leades so that seating the bullets well back from the rifling 0.030-0.060" can give better accuracy than crowding the rifling. I'd bet that this Sukalle rifle has a fairly sharp leade.

There's nothing quite like Ralph Gunriter and his 7 lb, half MOA (with all loads too) .300 Ultra Mag, who's got everyone convinced that if their hunting rifle can't shoot half MOA or better they shouldn't embarrass themselves by taking it into the woods. If a rifle can shoot 1 or 2 MOA, and the shooter can get the rifle to shoot that well from a field position he's good out to 300 yards on deer anyway. That's a pretty good distance, and a whole lot of people no matter how accurate the rifle would be hard pressed to hit a truck at 300 yards let alone a deer from a field position.

Now that I've insulted and offended a whole bunch of people I'll go away. :D
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Thank you for your common wisdom. I probably made a mistake looking for sub MOA accuracy from a field rifle. But owning a rifle built by a guy who did builds for Jack O'Connor makes me feel obligated to get the best out of the rifle possible. A lot of us would like to get bench accuracy from our field rifles. Today's manufacturers put a lot of emphasis on such. The one thing I like about vintage builds is the aesthetics that can only be evident when it is built by hand. Off the rack rifles today are going to be accurate but probably were never touched by human hand and look it.
 
While we are on the subject of Mauser actioned hunting rifles, let me tell you about a particular rifle that belonged to a friend. It was based on a Mexican Mauser, and was based on a sporterized military stock, and somtime in the distant past had been rebarreled to .257 Roberts, and then rechambered to the AI version without the barrel being set back. The fellow whose estate it came from was a retired CHP who had worked as an investigator for the local DAs office, and who had had a long time friendship with a local pawn shop owner. Over a number of years he had picked up military Mausers and sporterized them. This particular rifle had a somewhat unique bedding system. There was a thin flexible barrel band near the front of the stock, that was held in place by a cross bolt through the sides of the stock, that also acted as the hinge pin for a squared non-swiveling sling loop. With this in place, and the front action screw secured, the tang of the action, rather thin and flexible in Mausers, was above the stock by a good eighth of an inch or more, and tightening the rear action screw would bring it into contact with the stock, without permanently bending it. The extent of the deformation was such that when I mounted an inexpensive old Japanese 4X scope for him, using Weaver bases and mounts, I had to find a slightly thicker rear base, in order to be able to sight the rifle in. (No, I do not normally participate in projects that have these sorts of attributes, but the scope mounting was the extent of my commitment, and was done as a favor.) Since the rifle came with fire formed brass, and dies, I made a WAG and loaded some test ammo to do a final sight in and see what sort of accuracy this unique "bedding" system resulted in. Surprise, surprise, it shot just under 3/4 inch. While I was at the range, I removed the front band, which resulted in the barrel floating in the forend, and tried a few shots. It shot about an inch and a half. This was with the original military action bedding. Since the rifle would only be used as a deer rifle at reasonable ranges, I put the band back on the barrel, rechecked the scope setting, and pronounced the project a success. As far as I know, the rifle lived out the rest of my friend's life in his gun safe, along with other firearms that were bought on whims, shot a little and put away. I don't think that he ever took any of them on a hunt, with the exception of his shotgun, and a .223 that he liked to shoot ground squirrels with.
 
That would bring up another topic. Does a rifle shoot better fully inletted, assuming a skilled craftsman, or free floated. Someone took it upon themselves to free float and add glass to the bedding of the Sukalle. I have it on very good authority that the original stock work was done by Howe of Griffin and Howe. I wish they would have left it alone. I wonder how it would shoot if left in its original state. My Remington 700VLS in .308 is fully inletted and will shoot 3/8 " groups at 100 yds. I have read that people have had to go to the lengths of glass and free floating to get this rifle to shoot under 1".

My trip to the range today yielded promising results with 55.3gns of 4350. I will work around both sides of the load and if I achieve good results I may try using some card stock in various points in the barrel channel to see how it affects the groups.
 
If your 700 VLS is "fully inletted", it is entirely by accident. The barrel is intended to be free floating. People argue a bit about the first 1" or 2" of the barrel being supported, but a rifle that is fully floated from there will almost always be best. Some rifles do shoot better with a "pressure pad" at the very tip of the forend. I've never heard of a benchrest rifle with that kind of setup.

The vastly overwhelming majority of short range benchrest rifles are glued in, pillar bedded or glued-and-screwed (which is like a combination of the two). All of these are closely related to "glass bedding" and are generally considered to be preferable to other bedding methods.

Some long range rifles with heavy barrels use a bedding block form of bedding where a bedding block clamps the barrel in front of the action. The block is bedded into the stock. In this case, the rest of the barrel *and* the action are free floating.

I sent you a very detailed PM. It may insult your intelligence. If so, I apologize. I just wanted to cover all bases.

Best regards,

Greg Jennings
 
I don't remember ever seeing a factory Remington that did not have a pressure point. Most of the time the machine bedding is not close enough to stabilize the barreled action without one, unless the additional step of bedding the action is taken. I have seen fellows, who did not know this float barrels without bedding the action, and the results were not good. A friend had a 722 that was done this way, and you could rock the action from side to side in the stock after the action screws were tightened. A bedding job fixed the problem, and much improved the accuracy.
 
Factory Remington Rifles

Boyd Allen said:
I don't remember ever seeing a factory Remington that did not have a pressure point.
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Several years back, I purchased five factory Remington 700 Sendero rifles, .223,.308,.25-06,.7mm Mag and .300 win mag. All came with floated heavy barrels and aluminum bedding blocks.




Glenn
 
I don't know if it is a good definition, but what I was referring to was a short section of a stock's barrel channel, just back of the forend tip, that is higher than the rest so that it makes contact with the barrel, exerting some upward pressure on it. Typically, there are a machined feature in factory wood stocks. In these situations, assuming that there has been no barrel contour change, floating the barrel primarily consists of removing this contact point, so that the clearance between barrel and stock is the same as in other areas of the barrel channel.
 
Boyd Allen said:
My bad. I had wood stocks on the brain. Has anyone seen a wood stock that came without a pressure point?
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Wood stock without a pressure point. I Bought a Remington 700 BDL from a friend that came from the Remington Custom shop(Verified). It came with the most beautiful factory wood stock I've ever seen. The stock did not have a pressure point. I sold the stock and replaced it with a composite stock. That wood stock was too pretty to take on hunting trips.



Glenn
 
Pressure Point

Some factory hunting rifles seem to shoot better with a "pressure Point" about a 1/2 inch from the Stock forend. I don't think it really matters whether the stock is wood or composite. When I buy a hunting rifle, I immediately bed the action and free float the barrel. A pressure point on a floated barrel is simple. Remove the action. Place a small dab of epoxy about 1/2 inch from Stock forend. Apply release agent to the barrel section that contacts epoxy. Place action in stock. Secure barreled action to stock with masking tape. Let epoxy set. After removing tape and cleaning up,place action in stock and tighten stock screws. Go to range and shoot. Add or reduce pressure by sanding down epoxy. I've done this several times. Sometimes it works and sometimes it doesn't. I end up simply removing the pressure point if the gun doesn't shoot to my satisfaction.




Glenn
 
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Thanks Boyd. That's what I was calling a "pressure pad" in an earlier post. I've seen several with and several without.

My goto rifle for most of my adult life was a post 64 / pre 85 M70 in 243. It didn't have one. That rifle, now reincarnated as a 260, has been passed down to my son and is pillar bedded. It has always been a shooter. Of course, it's better now.

My second big rifle was a M700 Sendero in 300 Win Mag. It came from the factory in a HS Precision-ish stock with a bedding block. Its bedding was FUBAR. The inlet was crooked. So, it had a pressure point, but it was on the side. It was no fun. I threw the stock in the trash and bought another that someone was parting out. I opened it up a hair...by dremel and by hand...and skim bedded it over the bedding block. It shot much better after that. However, I do not find a Sendero-weight 300 WinMag fun to shoot, so I moved it along.

My current hunting rifle is a Tikka T-3. I need to check it to see if it's floated. Just a reminder to myself to get it back from the young man that I loaned it to... I can tell you that it's a very nice shooting little rifle. I sure like that little action. Update - The Tikka website says that the barrel is free floating. Of course, that means zilch.

Greg J.
 
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