Gunsmithing Bedding Mini Chassis

[blackfoot]

Question on bedding a Manners Mini Chassis. It seems that when you tighten the action screws it kind of sucks the action down into somewhat of a v block. So if you are going to bed it, not just the lug, how would you do it stress free since it seems the design is to put stress on the action?

 

[LRI]

Here's an alternative to resin into your bedding block.

Fixture the stock in a machine vice, drill/tap the rear guard screw hole for a larger sized bolt, say a 9/16. drill a 5/16" hole through the 9/16" bolt. Screw it into the tapped hole to a depth where it will be a smidge proud on your action's underside. now wrap a piece of snorty emery cloth around your receiver and carefully sand/lap the screw till it has some contour mirroring your receiver. Go to where the action just starts to rub on the stock's V bed. You could wick a dot or two of thin superglue into the threads to lock it in that position or epoxy/loc tite it ahead of time.

Now the rear of the action is supported directly to where the guard screw is tugging on it. Mitigates the risk of distortion.


Your done and it never flakes off or chips down the road.

I've not done this yet. It's been in my mind to go for it soon as I have a chance. No reason it won't work though.


C.

 

[Bob L Swagger]

Some smiths bed the tang area of the mini chassis... A friend of mine has a rifle built by Jon Beanland in a mini chassi & this was done. The rifle is a 6.5x47L & it shoots in the .1's.

 

[Sixfivesavage]

I've had one in a chassis bedded and now have one that I put together myself in my kitchen. The professionally built rifle shot well although I never really worked up a load for it before I sold it. The one I have now that I did myself has a CBI prefit on it and it has shot in the ones quite a few times. I know its subjective but I don't see enough if any of a reason to go through a permanent bedding process on a mini chassis unless it's just because you really want to. I do know I had feeding problems with the chassis that was bedded. For me, I don't think I'll ever bed a rifle again unless it's a conventional stock.

 

[blackfoot]

I know its subjective but I don't see enough if any of a reason to go through a permanent bedding process on a mini chassis unless it's just because you really want to.

I keep getting results like this:

There's three in the middle






I'm thinking there is more potential and maybe eliminate flyers with bedding??

 

[Sixfivesavage]

Maybe, maybe not. Is everything torqued correctly? Tried changing you seating depth? Different primers? Are you any good at shooting groups?

 

[blackfoot]

Maybe, maybe not. Is everything torqued correctly? Tried changing you seating depth? Different primers? Are you any good at shooting groups?

Wouldn't be talking bedding if I hadn't. Everything except primers, which I've never found to make a huge difference. I don't think there is enough time/barrel life/components to chase every variable with loads. Ain't my first rodeo but I'm open to opinions/suggestions.

 

[Sixfivesavage]

Yea, I hear ya. I don't me a to insult you, just covering the bases. Could very well be the bedding. I like the sounds of chads idea, shouldn't cause any feeding issues. Whatever you do, hope it works out for you.

 

[STR]

Do as you may, but I personally would follow Manners instruction to a tee which doesn't call for any kind of bedding, and go shoot your rifle. The last three rifles I've put into Manners Mini Chassis shot super tight groups without bedding. Plus I'm sure right now you're not thinking of resale, but try to sell a bedded Mini Chassis vs not bedded.

 

[Canepole]

Is the chassis system just as accurate as a stock with bedding?

 

[Mike]

I keep getting results like this:

There's three in the middle






I'm thinking there is more potential and maybe eliminate flyers with bedding??

Sorry to burst your bubble but that's more likely your shooting.

 

[Rob01]

Got a T3 with a mini chassis in a few weeks back for my .308 and just bolted it in to Manner's spec and when I hit the range it shot the same as when it was in the fully bedded McMillan HTG stock that the barreled action was in before. I wouldn't mess with bedding one unless you found a need just like in any other chassis system.

 

[blackfoot]

Sorry to burst your bubble but that's more likely your shooting.

Maybe. I'm open to the possibility. Maybe stock design that I'm not used to. I will say I have much more consistent results with other rifles, even ones that weight half of this one in the same cartridge. I did relieve the barrel channel a little more and also found the bolt handle was touching the stock, so I relieved that area also. See if that helps.

Is there something in particular you see I might be doing in regards to shooting just from these results? This was shooting off a br front rest and rear bag.

 

[Rob01]

Have you let anyone else who shoots well try it?

 

[Canepole]

Got a T3 with a mini chassis in a few weeks back for my .308 and just bolted it in to Manner's spec and when I hit the range it shot the same as when it was in the fully bedded McMillan HTG stock that the barreled action was in before. I wouldn't mess with bedding one unless you found a need just like in any other chassis system.

Thanks, that answers my question. Manners mini chassis it is. One stock for 2 barreled actions?

 

[Mike]

As Rob just mentioned I would have someone else who you know shoots well try it first. I am not saying your stock doesn't have an issue however as Rob has eluded to and as my own experience shows, there should not be any difference at all. The entire reason for Tom Manners inventing the Mini Chassis is to prevent the need for bedding. Also, it could very well just be the comfort factor of the stock.

But in analyzing your shooting, the first and third pics show significant horizontal stringing. This could be a number of things including NPOA, trigger control, shoulder position. The fact that you are also showing vertical "flyers" indicates you may have some positional issues with the stock in your shoulder or breathing. Again, have someone else shoot the stock for you and see there results.

 

[blackfoot]

Have you let anyone else who shoots well try it?

Not yet. Messing with loads is all so far. 139 rounds down the pipe. Showing potential, just have to fine tune. The targets above are all different loads.

 

[BillyGoatMachine]

IMHO bedding a mini chassis defeats the purpose of the system. If your so inclined to have a bedded stock, get another Manners without the mini chassis as they are around $300 cheaper. Sell of your current stock for a profit. Personally, when my rifle add kicks in I can swap out barreled actions if need be on my mini chassis. Also, another here that doesn't think the mini chassis is the culprit for your fliers.

 

[blackfoot]

I find it surprising how definitive some are that there is NO difference, when Tom Manners himself in a thread on this forum said there is a difference, and for a competition (f-class or br) gun he would have a bedded stock. Also, GAP, who seems to have a pretty good relationship with Manners, beds the lugs on the mini chassis. So the original question was just, if you are going to bed one, which some people do, how would you bed stress free since the design of the v block imparts stress? I'm probably not going to bed it, but Tom Manners himself indicated there might be a .100" difference in group size from a bedded rifle and his mini chassis, but it's very difficult to evaluate.

I'm inclined to think my "flyers" are possibly from the stock and barrel/bolt touching and/or getting used to the stock/shooter error. I've relieved the clearance on the barrel and bolt so I will be shooting some more to evaluate that and paying more attention to technique while shooting. I'm curious to see how it works out.

 

[drglock]

T4A with mini chassis(not bedded) .308 built by PCR

 

[Mike]

I find it surprising how definitive some are that there is NO difference, when Tom Manners himself in a thread on this forum said there is a difference, and for a competition (f-class or br) gun he would have a bedded stock. Also, GAP, who seems to have a pretty good relationship with Manners, beds the lugs on the mini chassis. So the original question was just, if you are going to bed one, which some people do, how would you bed stress free since the design of the v block imparts stress? I'm probably not going to bed it, but Tom Manners himself indicated there might be a .100" difference in group size from a bedded rifle and his mini chassis, but it's very difficult to evaluate.

Blackfoot. You have to be careful not to contradict yourself. First, you have to discover the "context". Tom saying there is "No" difference is really "no discernible difference". The fact you quote Tom himself as saying "Tom Manners himself indicated there might be a .100" difference in group size from a bedded rifle and his mini chassis, but it's very difficult to evaluate." shows this.

I'm a pretty decent shot and I can't shoot .1 difference. And to be honest, I doubt anyone except hardcore BR or Fclass guys could either. It's the same with GAP. GAP does what the customer wants, they do not tell the customer what to do. If the customer waffles on whether or not to have it bedded, they will usually bed it not out of necessity, but rather out of peace of mind for the customer. It's very similar with AI chassis.

If I were you I would eliminate the easier variable first before delving into the potential differences between bedded and non-bedded mini chassis.

 

[blackfoot]

GAP beds them on standard rifles they offer, not just if you request it on a build. I would imagine there is a reason for it and not customers asking that it be done. There are other reputable smiths who have expressed a need to bed them. I originally inquired out of wanting to eliminate variables. I have and have had rifles that I am able to shoot consistently in the .1 to .3 range without the kind of flyers I was getting. The possibility of bedding was a variable I was considering at some point, after trying to eliminate other variables. I didn't say I was going to go out and bed the thing today or tomorrow. I have said that I am open to shooter error, but there are reasons I don't think it's the whole issue. I have had rifles that, if they went from a .250" gun to a .350" gun, I would know something was up. But the intended purpose of this rifle doesn't justify that scrutiny, and I most likely won't bed it.

There still has only been one answer to the original question, and that was from Chad. Main reason I asked was because I wonder why people bed them, or how, if the whole point is to have stress free bedding, and the v block design imparts stress. So when you bed them, you are basically eliminating the advantage of the whole design, correct?

 

[Rthur]

You may want to check for clearance issues around your trigger.


R

 

[tmanners]

Question on bedding a Manners Mini Chassis. It seems that when you tighten the action screws it kind of sucks the action down into somewhat of a v block. So if you are going to bed it, not just the lug, how would you do it stress free since it seems the design is to put stress on the action?

Hi Blackfoot, Below is a copy of a post that I did a few years ago on the mini chasiss, I think that it will help you out. Also PM your phone number and I will give you a buzz, I want to make sure that the action, trigger and barrel are all sitting as they should in your stock. Thank you very much,.


(quote ) The MCS-mini chassis is a V block design system, which in our opinion is the best design to fit the original purpose of the mini chassis. The original purpose of the mini chassis was to develop a high end drop in and go DBM system for a tactical/hunting stock with ability to be used with a wide varity of actions that did not require bedding. The key word here is “ wide Varity of actions”. This was the hardest part of the design. . Even actions from the same manufacture will not always be of the same diameter, shape, or even straight. To correct some of this difference, we designed the chassis so that it actually contacts the action in about five different points. First - the back of the lug area, Second/Third - about 1” contact on both sides of the action from the lug area backward, Fourth/Fifth – both sides of the tang area from the back action screw forward. The complete tang does not float only the very tip of the tang. The reasons that the bottom of the action and the tip of the tang float, is that not all actions are the same diameter and we want to make sure that the action is draw down and centered in the chassis. I would much rather have the action setting centered in a V block than one that is rocking side to side on the bottom of the action. In a perfect world the best chassis design would be a 100% machined, contoured, and matched fit to each action, but its not a perfect world.

I think what happens is that guy’s loose site on what the mini chassis was designed for. During the first test on the prototype chassis we took one of my older Rem 700 6mmBR guns and used it as a test bed. This gun will easily shoot in the very low .200” groups all day long. The first groups where shot in the fully bedded 100% carbon fiber bench rest stock. Then we droped it into an MCS-T4A with a mini chassis. The groups opend up about .100”. Was the .100” due to the chassis or because we went from a full bench gun riding in mechanical front/rear rests/bags, which was shot free recoil to a tactical stock shot off a bipod and a rear bag? Being a stock maker I got a pretty good idea on what caused the groups to open up, not all of the difference, but a lot was due to the way the two stocks road the bags or lag of.

Bottom line is, do what gives you the most confidence in your rig. You can have a million dollar rig, but if you don’t have confidence in it, you aint going to hit shit. Some guys will bed the chassis just like they do a AI, others will do just the lug. But most ( 99% ) will just bolt it up and go. The chassis are proven shooters. Keep in mind the purpose of the chassis when I say, I dont think you are going to gain anything by doing a full bed job on a chassis, if you are building a gun that you plan on bedding, do a full pillar bed job from the start. When I build my own personnel guns, if it is a tatical comp gun I use a chassis. On the other hand, if I am doing a full blown F-class, or bench gun, where I am going to gain all the advantages of the stock and other equipment, I do a full stress free pillar bed job. Again do what gives you the most confidence.

 

[blackfoot]

You may want to check for clearance issues around your trigger.


R

Thanks for the tip. I already did that and had to relieve some areas on the trigger guard. It clears the chassis but the trigger guard was pressing on the trigger. That was a while back.

Thanks Tom, that was the post I was referring to on the mini chassis. Pretty sure everything is now sitting in the stock as it should at this point. As I said before, I relieved some area around the bolt handle because it was touching, and opened the barrel channel slightly to fully float the barrel. Haven't shot it since then. There looks to be good bearing across the lug, two identical length marks on the front of the receiver where it bears on the chassis, and two on the tang also. The trigger is clear from touching the chassis and the trigger guard. Part of the reason I had asked about the bedding was that if you bed them, unless you installed some sort of raised pillar as Chad suggested, the action would then be sitting completely on bedding material with no pillar completely through to engage the action. I've always been told that is not good, so I don't see how "fully" bedding a chassis is a viable option. But it's just a question, I don't know. Not sure how much of the lug GAP beds as I've never seen one disassembled, but I assume not enough to keep if from centering in the v block?

 

[scotharr]

As I read Tom's response, he thinks most of the .100" difference between bedded & mini-chassis grouping was the fact that he went from a pedestal rest to a bipod. IMHO, this was not a great test because he changed more than the bedding system, he also changed the stock and how it was stabilized (rest vs stock). Given the other changes made, it's quite possible the v-block was every bit as good as the bedded system. Another data point, my family shoots a lot of F-Class from 500 out to 1K just about every weekend and all our stocks use unbedded Whidden v-blocks. Based on our results over a long period of time, I am confident v-blocks are just as effective as a full bedding job. If I had even a smidgen of a doubt, I would bed all my rifles, but that is not the case. We are shooting 308 WIN and 284 Shehane...cartridges with quite a bit of recoil and they work flawlessly.

In addition, I remove my stock every time I clean it....just easier that way. They all return to zero with no issues and I don't have to worry about damaging that precious delicate bedding.

Scott

PS. on my first v-block stock, I took the advice of some of my benchrest friends and bedded my v-block...what a mistake. Sure the stock shot great bedded, but the inevitable occurred....I switched actions. Even though the action is exactly the "same" model, it does not fit the bedded stock stress free. Now I have to relieve the bedding and re skim-bed it.....ARGHHHHH.....what a F*(*#@A hassle! Instead I'm gonna mill out the whole damned thing and reinstall another Whidden bedding block....like I should have left it in the first place.

 

[blackfoot]

Thanks for all the advice guys. I'm hopeful that I can get it nailed down. Pretty sure at this point I've got the stock aspect nailed down and can eliminate that variable on the next outing tomorrow.

I did have a 6BR that I just bolted into a HS Precision aluminum bedding block. That thing would agg in the .2's and low .3's (average of 5 - 5 shot groups), and was just a trued up Remington. Most people said I would need to bed it but I obviously didn't screw with it. The Manners system seems to be a better mousetrap.

 

[kalindark]

You will be fine. I have a manners T5a with mini-chassis and will never bed it.


When I don't shoot groups like what is pictured above, I can only blame myself.

 

[blackfoot]

Well after relieving some area around the barrel and the bolt, changing the torque to 65 and 45 (was using 65 and 60), and paying better attention to technique, flyers were eliminated. This is 61.8 grains of RL17 under a 215 Berger Hybrid running 2925. I would say there is no need to bed Not sure what made the difference, I think a little of both the clearance and paying better attention to technique (firmer hold and constant pressure on the shoulder). On a group similar to this with another load I had one shot with less pressure on the recoil pad that was about 1/2 high from the rest of the group, so I could definitely tell that caused a vertical flyer. Thanks for all the advice, even though my original question never got addressed, except for partially by Chad. BTW, this was a LRI group buy Remington 700 chambering job, so hats off to LRI for a wicked accurate chambering.

5 Rounds:

 

[chipsfan]

Well after relieving some area around the barrel and the bolt, changing the torque to 65 and 45 (was using 65 and 60), and paying better attention to technique, flyers were eliminated. This is 61.8 grains of RL17 under a 215 Berger Hybrid running 2925. I would say there is no need to bed Not sure what made the difference, I think a little of both the clearance and paying better attention to technique (firmer hold and constant pressure on the shoulder). On a group similar to this with another load I had one shot with less pressure on the recoil pad that was about 1/2 high from the rest of the group, so I could definitely tell that caused a vertical flyer. Thanks for all the advice, even though my original question never got addressed, except for partially by Chad. BTW, this was a LRI group buy Remington 700 chambering job, so hats off to LRI for a wicked accurate chambering.

5 Rounds:

What cartridge?

 

[blackfoot]

300wsm

 

[chipsfan]

Looking good man. What barrel length with those velocities?

 

[blackfoot]

26" Krieger 5R, 1:10 twist