Bedding MPA Chassis

[FourT6and2]

Those of you who have MPA chassis... did you choose to have them bedded or not? Has anybody done a before/after to see if performance was increased by bedding? I'm thinking of getting two different actions to try out in the same chassis and that would obviously render bedding moot until I decide to stick with one of the two actions.

 

[Thud]

Leave them be.

 

[Belisarius]

I have a couple of friends that skim bedded theirs
no record on before and after
one is a prs competitor, he wins a lot

 

[47guy]

Are you having issues that make you think it needs to be bedded?

 

[FourT6and2]

Are you having issues that make you think it needs to be bedded?

I don't have the chassis or actions yet. I'm thinking buying two different actions and one chassis so I can swap between the two. That would mean I can't bed the chassis. Just wondering if that's gonna be an issue.

 

[RedMan*]

Just send it.

 

[Sooner Sniper]

Not necessary

 

[47guy]

I don't have the chassis or actions yet. I'm thinking buying two different actions and one chassis so I can swap between the two. That would mean I can't bed the chassis. Just wondering if that's gonna be an issue.

i shot 3 MPA chassis for a few years...i pulled them apart many times to clean..change triggers ECT and can not remember ever having any big point of impact changes...i would not bed it personally because youll ruin the resale value should you decide to sell it and if your swapping actions...even if the same brand...chances are they will not be exactly the same.

 

[1moaoff]

I have 8 of them. None have been bedded. I have not seen any need to. If torqued correctly it should not be an issue. You will hear the rare occasion where its needed. But no documentation on why that I have seen. Swapping actions between chassis I dont understand. The chassis aren't really that much. Personally I think too many people take their rifles too far apart too often. But that's me.

 

[47guy]

I have 8 of them. None have been bedded. I have not seen any need to. If torqued correctly it should not be an issue. You will hear the rare occasion where its needed. But no documentation on why that I have seen. Swapping actions between chassis I dont understand. The chassis aren't really that much. Personally I think too many people take their rifles too far apart too often. But that's me.

a $1000 bucks to you may be nothing but keep in mind a lotta ppl do not make the money you do and have to save to buy quality gear.
When I started in this I made enough to pay my bills and had to be late on a couple to buy a savage.

 

[1moaoff]

a $1000 bucks to you may be nothing but keep in mind a lotta ppl do not make the money you do and have to save to buy quality gear.
When I started in this I made enough to pay my bills and had to be late on a couple to buy a savage.

I wasnt saying they are cheap.
My point was that on a rifle like we are likely discussing that is one of the least expensive parts.
They can be had for 600 and up on the PX, and dont wear out like a barrel. Generally less than a scope. Generally less than an action. So overall it's a lower cost component of the rifle.

I hear people wanting to swap barrels scopes and chassis regularly. It seems that most find out it's more of a pain than it's worth. It can also get you into trouble.

 

[1moaoff]

And keep in mind the OP was thinking about trying out 2 different actions in the same chassis. That changes the perspective a bit.

 

[wade2big]

i have seen too many rifles shoot consistent without bedding in manners, mcmillans, grayboe, multiple chassis, and even factory tupperware stocks that have been dremeled to freefloat the barrel to waste time and money with bedding of any kind.

 

[djarecke]

Robert Gradous considers it mandatory and that was my experience. I was getting 2 rounds through one hole and a flier every time no matter what I did with load development. I had it bedded and it was a one hole gun after that with a tuning node like I would have expected from that caliber.

 

[Dthomas3523]

Robert Gradous considers it mandatory and that was my experience. I was getting 2 rounds through one hole and a flier every time no matter what I did with load development. I had it bedded and it was a one hole gun after that with a tuning node like I would have expected from that caliber.

Yep. My thoughts are, you can either test out the chassis and see if it needs bedding, or just bed it and be don’t with it.

For the relatively cheap price of bedding, once I know a rifle is going to stay with that chassis, it’s gets bedded. I’d rather pay the small amount and know it’s perfect than to have to find out on my own.

My current lone peak/XLR doesn’t exhibit any signs that it needs bedding, but as soon as I get a lull between matches, it will be.

 

[FourT6and2]

Yep. My thoughts are, you can either test out the chassis and see if it needs bedding, or just bed it and be don’t with it.

For the relatively cheap price of bedding, once I know a rifle is going to stay with that chassis, it’s gets bedded. I’d rather pay the small amount and know it’s perfect than to have to find out on my own.

My current lone peak/XLR doesn’t exhibit any signs that it needs bedding, but as soon as I get a lull between matches, it will be.

Yeah this is where I'm at as well. I want to try out both actions and then stick with the one I like more. And then I will have the chassis bedded. Unless it shoots great from the get-go, I suppose.

 

[Dthomas3523]

Here you go. Straight from the MPA man himself:

Precision Rifle Media

You're listening to Precision Rifle Media brought to you by Bison Tactical. Located in Boulder Colorado, Bison Tactical has all your top-of-the-line precision shooting equipment from Laser Range Finders to suppressors, and tripods to reloading equipment, Bison Tactical has what you need to increase

www.precisionriflemedia.com

 

[FourT6and2]

Here you go. Straight from the MPA man himself:

Precision Rifle Media

You're listening to Precision Rifle Media brought to you by Bison Tactical. Located in Boulder Colorado, Bison Tactical has all your top-of-the-line precision shooting equipment from Laser Range Finders to suppressors, and tripods to reloading equipment, Bison Tactical has what you need to increase

www.precisionriflemedia.com

Will give it a listen, thanks.

 

[FourT6and2]

Well I'll be bedding the chassis once I decide which action to stick with long-term.

At 15:30 he says, "Aluminum is very stiff... There are some benefits to the v-bedding system... On premium actions, there are a lot of them today that you can just basically drop right into the v-bedding and [bedding isn't] really required to get ridiculous performance..."

Then at 17:30 the host asks specifically about bedding chassis and if it improves accuracy. Phil Cashin says he recommends bedding and that there's always an anomaly somewhere in the system (whether from the action or the chassis). And that he's encountered actions and MPA chassis that were out of flat/round with each other in the tenths.

Then at 23:12 he says, "If you want to get the absolute best [performance] out of [your rifle], without question... bed it."

Then he says, "Probably 80% of his customers do NOT bed their chassis. Obviously if there were accuracy issues related to the v-bedding system, there would be a much greater percentage of shooters who bed their chassis... I don't bed any of mine."

So WTF. Seems like a bunch of mixed messages.

 

[Dthomas3523]

Well I'll be bedding the chassis once I decide which action to stick with long-term.

At 15:30 he says, "Aluminum is very stiff... There are some benefits to the v-bedding system... On premium actions, there are a lot of them today that you can just basically drop right into the v-bedding and [bedding isn't] really required to get ridiculous performance..."

Then at 17:30 the host asks specifically about bedding chassis and if it improves accuracy. Phil Cashin says he recommends bedding and that there's always an anomaly somewhere in the system (whether from the action or the chassis). And that he's encountered actions and MPA chassis that were out of flat/round with each other in the tenths.

Then at 23:12 he says, "If you want to get the absolute best [performance] out of [your rifle], without question... bed it."

Then he says, "Probably 80% of his customers do NOT bed their chassis. Obviously if there were accuracy issues related to the v-bedding system, there would be a much greater percentage of shooters who bed their chassis... I don't bed any of mine."

So WTF. Seems like a bunch of mixed messages.

Message not mixed at all.

He’s saying bedding can only either A) do nothing or B) help.

80% of people are happy with the performance of the rifle without bedding. But if you are looking to squeeze all you can out of the rifle, bed it. Similar argument to factory ammo. Can you win with it? Yes. But if you want to exploit the full ability of your rifle, you need to hand load.

 

[R_Swanson]

Well I'll be bedding the chassis once I decide which action to stick with long-term.

At 15:30 he says, "Aluminum is very stiff... There are some benefits to the v-bedding system... On premium actions, there are a lot of them today that you can just basically drop right into the v-bedding and [bedding isn't] really required to get ridiculous performance..."

Then at 17:30 the host asks specifically about bedding chassis and if it improves accuracy. Phil Cashin says he recommends bedding and that there's always an anomaly somewhere in the system (whether from the action or the chassis). And that he's encountered actions and MPA chassis that were out of flat/round with each other in the tenths.

Then at 23:12 he says, "If you want to get the absolute best [performance] out of [your rifle], without question... bed it."

Then he says, "Probably 80% of his customers do NOT bed their chassis. Obviously if there were accuracy issues related to the v-bedding system, there would be a much greater percentage of shooters who bed their chassis... I don't bed any of mine."

So WTF. Seems like a bunch of mixed messages.

He's not sending mixed messages. There's no right answer. In fact I think its pretty cool he went into such a long winded answer explaining the machining aspect of it. I think you're taking a bunch out of context.

Most of his conversation is actually discussing the actions, not the chassis. Specifically machined vs turned actions. He's saying those actions can be out of round to a measurement in the tenths. Not that they were both having issues... as he mentioned, its much easier to machine his V in aluminum the same every time vs machining that action.

Example: When he says if you want the absolute best performance in your quote around 23:12 he's specifically discussing fully machined actions that have integrated lugs and rails, rather than ones that are turned. He's not talking about turned actions, hence where the conversation goes and the fact he isn't bedding his action.

Of course, if you have a cheap stock Rem action, odds are that is out of round as well, hence why he mentions much earlier that you will often benefit from bedding it.

He's giving great guidance on what to do, at least I think. But theres no definitive answer.

 

[Dthomas3523]

He's not sending mixed messages. There's no right answer. In fact I think its pretty cool he went into such a long winded answer explaining the machining aspect of it. I think you're taking a bunch out of context.

Most of his conversation is actually discussing the actions, not the chassis. Specifically machined vs turned actions. He's saying those actions can be out of round to a measurement in the tenths. Not that they were both having issues... as he mentioned, its much easier to machine his V in aluminum the same every time vs machining that action.

Example: When he says if you want the absolute best performance in your quote around 23:12 he's specifically discussing fully machined actions that have integrated lugs and rails, rather than ones that are turned. He's not talking about turned actions, hence where the conversation goes and the fact he isn't bedding his action.

Of course, if you have a cheap stock Rem action, odds are that is out of round as well, hence why he mentions much earlier that you will often benefit from bedding it.

He's giving great guidance on what to do, at least I think. But theres no definitive answer.

Yep. He’s saying the chances of needing to bed an action with integral rail or recoil lug is higher than actions that are machined fully round.

The downside is the fully round are less stiff than integral rails and lugs. He person uses and axiom which is round and he feels mates up well enough not to need bedding.

 

[Prebanpaul]

I own three, none are bedded. They all shoot 1/3 or less. If you are switching actions you can not bed the rifle. If you bed the chassis you will either have a lot of work to every re sell it or take a huge hit on it. Bed away, Your better off saving you money and buying shooting components and shooting more vs the return your ever going to see with accuracy.

 

[FourT6and2]

I own three, none are bedded. They all shoot 1/3 or less. If you are switching actions you can not bed the rifle. If you bed the chassis you will either have a lot of work to every re sell it or take a huge hit on it. Bed away, Your better off saving you money and buying shooting components and shooting more vs the return your ever going to see with accuracy.

I'm not too concerned with resale value. I'm shooting the rifle for me, not setting it up for the next guy to use

 

[FourT6and2]

Good points all around. Yes, I agree that bedding certainly isn't going to hurt and that if I want to ensure I'm squeezing everything out of it, I need to bed. I guess that's what I'll do once I decide on which action to stick with.

 

[Prebanpaul]

Unless your going to shoot from a bench on every shot, use the best bullet brass powder and primers, reload and do every single step every single time (IE uniiform every primer pocket, anneal, trim,). You will never see the need to bed a MPA action from the chassis.

 

[FourT6and2]

Unless your going to shoot from a bench on every shot, use the best bullet brass powder and primers, reload and do every single step every single time (IE uniiform every primer pocket, anneal, trim,). You will never see the need to bed a MPA action from the chassis.

I'd simply like to match the performance of my current rifles, which are bedded in McMillan stocks. Just so happens those rifles shoot really well.

And btw, people I've talked to who say they needed to bed their chassis (MPA or otherwise) did so not because they were grouping .23 MOA instead of .12, they did it because their rifles wouldn't hold zero and wandered, or because there was considerable stress induced into the action. Not saying the chassis was to blame. But just like that podcast from MPA explained, it could just be a nature of the beast when working with certain combinations of products.

In any event, I've got a chassis ordered

 

[47guy]

I'd simply like to match the performance of my current rifles, which are bedded in McMillan stocks. Just so happens those rifles shoot really well.

And btw, people I've talked to who say they needed to bed their chassis (MPA or otherwise) did so not because they were grouping .23 MOA instead of .12, they did it because their rifles wouldn't hold zero and wandered, or because there was considerable stress induced into the action. Not saying the chassis was to blame. But just like that podcast from MPA explained, it could just be a nature of the beast when working with certain combinations of products.

In any event, I've got a chassis ordered

do what makes you more confident with your gear...at the end of the days it’s all that matters.

 

[FALex]

I bed mine but I'm a fan of bedding. I do not know enough to say whether ambient temps effect the amount of contact between the action and the chassis. The concern being the expansion and contraction of the metal in relation to the ambient temperature of the environment you're shooting in. I took an LE sniper course three years ago. One of the students had a Rem 700 in a McCree and it would not maintain zero.

Two of the instructors (one of them is very well known and a well-respected individual in the PR/LE sniper community) stated that the chassis was causing POI shifts. As the day would progress, it would get warmer, and the zero would not maintain consistency.

I 100% respect that instructor's input. Furthermore, I need my rifle to be consistent, obviously. The only thing you MIGHT lose, is resale value of the chassis should you elect to sell it in the future. However, if that is a non-issue (it wasn't a concern of mine), you lose nothing by bedding it.

All that being said, I also understand that this was 3 years ago. Much has changed in the way of chassis and the variety of offerings available nowadays, and I'm sure all of the offerings have only improved.

 

[aero22abflight]

Just curious, I bought a MPA BA from factory and put a MPA scope mount with a Nightforce ATARC 7-35 x-mil scope and the whole rifle weighs 18lbs. is that usually a standard weight for PRS shooting rifles?

 

[47guy]

Just curious, I bought a MPA BA from factory and put a MPA scope mount with a Nightforce ATARC 7-35 x-mil scope and the whole rifle weighs 18lbs. is that usually a standard weight for PRS shooting rifles?

my MPA chassis'd rifle weighed 21lbs...i shed 6lbs when i went back to a stock.

 

[aero22abflight]

my MPA chassis'd rifle weighed 21lbs...i shed 6lbs when i went back to a stock.

How did you shed 6lbs?

 

[47guy]

Got rid of the chassis with the weight kit and went back to a Manners stock

 

[aero22abflight]

Got rid of the chassis with the weight kit and went back to a Manners stock

What manner stock are you running?

 

[47guy]

What manner stock are you running?

PRS1 with mini chassis...one of the best decisions ive made...also went back to a single stage trigger...i was very inconsistent in my scores and looking back through my scores over the years it seemed to start when i started running chassis...ive only shot 5 matches this year but ive placed 1st or 2nd in all 5...for me a lighter rig and a stock work better.

 

[aero22abflight]

PRS1 with mini chassis...one of the best decisions ive made...also went back to a single stage trigger...i was very inconsistent in my scores and looking back through my scores over the years it seemed to start when i started running chassis...ive only shot 5 matches this year but ive placed 1st or 2nd in all 5...for me a lighter rig and a stock work better.

Thanks for the input. I love the concept of the MPA chassis, but the weight is a killer..for me. I will shoot more on the chassis but later may have to go for a lighter chassis. I love the style of the Manners chassis system especially in badlands and meadowlands camo. Thanks!

 

[morganlamprecht]

Gunsmithing - Bed or Not, MPA Competition chassis

I am not sure if I want to bed my MPA chassis. Has anyone found that theirs absolutely needed or did not need to be bedded?

www.snipershide.com

its less about small groups and more about holding zero while taking a beating

its easy to test if it needs it...if youre shooting a range gun and not hard on it, it may never show up...ive seen enough rifles have zero shifts, if im traveling to other states to shoot...its bedded and i aint worried about it

 

[djarecke]

Gunsmithing - Bed or Not, MPA Competition chassis

I am not sure if I want to bed my MPA chassis. Has anyone found that theirs absolutely needed or did not need to be bedded?

www.snipershide.com

its less about small groups and more about holding zero while taking a beating

its easy to test if it needs it...if youre shooting a range gun and not hard on it, it may never show up...ive seen enough rifles have zero shifts, if im traveling to other states to shoot...its bedded and i aint worried about it

Bingo.

 

[Ugly_Duck]

a $1000 bucks to you may be nothing but keep in mind a lotta ppl do not make the money you do and have to save to buy quality gear.
When I started in this I made enough to pay my bills and had to be late on a couple to buy a savage.

"Late on a couple to buy a savage" ...legit

 

[nsmith022]

Just got mine put together and didn't bed. We will see how it goes.

 

[acudaowner]

how would you know for sure there was an improvement ? how would you measure that improvement 1 ten thousandth of an inch or do you think your going to get more ? how much would it cost to bed a metal frame , and clean up if it does not improve anything that could be a long messy cleaning process in a tight space , while trying not to scratch stuff . well good luck if you do it and I hope it works out for you as you hope it will please send back photos of what started with and how it either imporved or did nothing for you also how you figured out if it was better or no differant .

 

[Dthomas3523]

how would you know for sure there was an improvement ? how would you measure that improvement 1 ten thousandth of an inch or do you think your going to get more ? how much would it cost to bed a metal frame , and clean up if it does not improve anything that could be a long messy cleaning process in a tight space , while trying not to scratch stuff . well good luck if you do it and I hope it works out for you as you hope it will please send back photos of what started with and how it either imporved or did nothing for you also how you figured out if it was better or no differant .

Costs the same to bed metal as it does fiberglass.

You don’t take it out if it didn’t improve as it won’t hurt anything to stay bedded.

 

[nsmith022]

I'm running a TL3 in a Matrix so I hope so!

 

[ExhaleAndSqueeze]

Here's part of my litmus test for bedding. First, determine if there's flex in the action. Put the action in the chassis, bolt the action screws in loosely, stand the rifle up on the butt, tighten the rear action screw, tighten the front action screw, torque them. Then slowly loosen the front screw until you feel the thread engagement give way to a lack of tension. Once you're at this point slowly loosen and tighten the screw, playing with the thread engagement. Watch the front of the action as it disappears into the chassis and/ or place a finger on the gap where the barrel exits the chassis on the tip of the forend. One part of the finger on the chassis, one part on the barrel so you can feel the gap shrinking or widening. As the threads engage, if it pulls the action into the inlet it is flexing the action to do so. If you can feel or see the action raising out of the inlet or sucking in, it's being torqued. Usually at the tang.

I had to bed every XLR chassis I had. One particular rifle shot very well but had a definitive cold bore shift. Every time. Bedding it fixed it. I have 4 MPA chassis and have only bedded one. And it is the MPA AI AT chassis. That's a whole norther story. The Bighorn TL3s are gtg in the MPAs and the RIMXs are as well.

Thank you so much for clarifying on that the TL3 is gtg w/o bedding. Had to read all the way to the bottom, but in general the above conversation has been extremely informative.

 

[ExhaleAndSqueeze]

Not yet, but i plan to tonight.

 

[jsel10]

Here's part of my litmus test for bedding. First, determine if there's flex in the action. Put the action in the chassis, bolt the action screws in loosely, stand the rifle up on the butt, tighten the rear action screw, tighten the front action screw, torque them. Then slowly loosen the front screw until you feel the thread engagement give way to a lack of tension. Once you're at this point slowly loosen and tighten the screw, playing with the thread engagement. Watch the front of the action as it disappears into the chassis and/ or place a finger on the gap where the barrel exits the chassis on the tip of the forend. One part of the finger on the chassis, one part on the barrel so you can feel the gap shrinking or widening. As the threads engage, if it pulls the action into the inlet it is flexing the action to do so. If you can feel or see the action raising out of the inlet or sucking in, it's being torqued. Usually at the tang.

I had to bed every XLR chassis I had. One particular rifle shot very well but had a definitive cold bore shift. Every time. Bedding it fixed it. I have 4 MPA chassis and have only bedded one. And it is the MPA AI AT chassis. That's a whole norther story. The Bighorn TL3s are gtg in the MPAs and the RIMXs are as well.

Great info here. This exact test caused me to bed my MDT ACC chassis.

 

[dwent]

Here's part of my litmus test for bedding. First, determine if there's flex in the action. Put the action in the chassis, bolt the action screws in loosely, stand the rifle up on the butt, tighten the rear action screw, tighten the front action screw, torque them. Then slowly loosen the front screw until you feel the thread engagement give way to a lack of tension. Once you're at this point slowly loosen and tighten the screw, playing with the thread engagement. Watch the front of the action as it disappears into the chassis and/ or place a finger on the gap where the barrel exits the chassis on the tip of the forend. One part of the finger on the chassis, one part on the barrel so you can feel the gap shrinking or widening. As the threads engage, if it pulls the action into the inlet it is flexing the action to do so. If you can feel or see the action raising out of the inlet or sucking in, it's being torqued. Usually at the tang.

I had to bed every XLR chassis I had. One particular rifle shot very well but had a definitive cold bore shift. Every time. Bedding it fixed it. I have 4 MPA chassis and have only bedded one. And it is the MPA AI AT chassis. That's a whole norther story. The Bighorn TL3s are gtg in the MPAs and the RIMXs are as well.

Sorry to revive but didn’t want to make yet another thread on the issue.

If I’m understanding correctly with the MPA v blocks, this flexing scenario shouldn’t be possible since the action screws are positioned within the v block area both behind the lug and on the tang, right?

I have 300 PRC Proof carbon/Origin in a BA Ultralight and my groups are wandering. Also I’ll get two in one hole, then another 1.25” away. I can shoot .24” with my other gun, it’s not me. SDs are single digits and concentricity and neck tension are consistent. I’m at my wits end with this rifle and considering bedding the lug and tang areas. I have good contact along the V area. The lug has partial contact marks from the barrel to about half way down. My front action screw refuses to stay torqued, despite the not-so-wedge lock bolts MPA provides and blue loc tite. I have also bedded the rear most two inches of the pinned scope base as it was not flat when torqued to spec.

I have no science to back this up but with the idea of metal bolted to metal under heavy recoil, it just seems like adding some more material in there for support and maybe a small amount of compression could be beneficial.

 

[1moaoff]

Fix the action screw issue before anything else.

What are the other clambering you shoot sub .250" ??? Is that nearly every time you shoot them?

 

[dwent]

Fix the action screw issue before anything else.

What are the other clambering you shoot sub .250" ??? Is that nearly every time you shoot them?

Well, I’m out of ideas on the action screw. I have read someone else post a similar issue with their MPA and bedding the lug eliminated the action screw problem.

Other rifle is a factory bergara HMR premier in .308. 1/4” is a good day but it’s happened often enough to not be a fluke. It’ll shoot in the 3s and 4s pretty consistently.

 

[700rem]

Torque it down & send 'em