Impact 737 and aics stock

[Rickyd]

As above really, I’m tinkering with the idea of a .22-250. Potentially with a 737r action and a AICS stock and carbon barrel. Will this action fit the stock perfectly? 

[Ronin]

No

 

the Rem clones and Rem 700 are never a perfect all contact fit in any chassis including AiCS and any chassis that is “inlet for specific action”

 

One usually finds there is waterline contact along the length of the action on either side 

Appropriate skim bedding will address this though and provide stress free contact when action screws torqued 

[Rickyd]

Very interesting, thanks for the info 

[Catch-22]

Just stick the Impact into an MPA Competition chassis - I had one built a few years ago complete with several barrels of each 6.5x47 and .223AI and it’s a great shooter.

Ive never been a fan of the grip on my AI, the MPA is much better.

[Ronin]

@Catch-22 

 

Could you post a pic of the MPA action inlet (current) - intrigued to see if there are any witness marks showing on inlet or action base of the Inpact ,,,after several years of use in the chassis 

 

 

[Catch-22]

On 4/18/2024 at 10:46 AM, Ronin said:

@Catch-22 

 

Could you post a pic of the MPA action inlet (current) - intrigued to see if there are any witness marks showing on inlet or action base of the Inpact ,,,after several years of use in the chassis 

 

 

Here you go Andy.

Theres nothing on the chassis to suggest movement.

I have marred the action finish a bit due to some Redline High Pressure grease I used on the bolt lugs reacting to some left over cleaning solvents unfortunately. I think this trickled down via the front action screw and got between the chassis and action unknowingly and wore away some of the actions surface finish between a cleaning one time. But it’s all cosmetic. Needless to say I don’t use Redline on my bolt lugs, I’ve gone back to the MilTec and take extra care now flushing the chamber and bore with isopropyl alcohol.

Back to your question, I don’t see any signs of actual action movement in the chassis - which is good.

If this was an F class rig, it would be bedded as a minimum, more likely glued and screwed. But for range/PRS style use, I think it’s fine!

Interesting write up on PRS blog. Seems 50% of the top shooters skim bed their chassis. The reason given was not because they see accurate improvements or anything. It’s more they’re using it as an insurance policy in case they bang or drop the rifle during a strange at a match. But none seem to say it’s crucial to them. Again, f class is a whole different kettle of fish.

[Ronin]

Thanks for the pics and explanation re the contamination 

 

the pics of the chassis show some witness marks (tang area and around forward action screw hole 

There are also witness marks on the action in similar areas 

There doesn’t need to be any movement under recoil to create these marks 

It highlights my point that even inlets thy replicate certain actions are not 100% contact and will cause stress in an action when torqued down due to elasticity of the materials and the high forces generated (even at 50 inch pounds) that’s enough to bend the action or pull it out of shape 

This will have an adverse reaction to accuracy 

How much is dependant on where and how much movement there is in the action and it’s effect on contact surfaces of bolt lug : abutments : barrel tenon 

An example - last week I bedded a HS Prevision stock (alloy v block design in let) to a rifle I built two years ago, the rifle was put in a used pre bedded stock (bedded to another action) bought post build by the client - it shot sub half Moa in that stock

I had some pictures back yesterday of groups shot with the rifle in the stock I bedded 

Single hole, consistently repeatable groups 

That demonstrates the importance of mating the action to the inlet with bedding 

This isn’t the first time such improvements  have been highlighted 

The rifle in question is for deer work - I’d recommend anyone with a comp gun give thought to this simple but effective improvement to their chassis based “system”

 

 

[lapua]

17 hours ago, Catch-22 said:

Here you go Andy.

Theres nothing on the chassis to suggest movement.

I have marred the action finish a bit due to some Redline High Pressure grease I used on the bolt lugs reacting to some left over cleaning solvents unfortunately. I think this trickled down via the front action screw and got between the chassis and action unknowingly and wore away some of the actions surface finish between a cleaning one time. But it’s all cosmetic. Needless to say I don’t use Redline on my bolt lugs, I’ve gone back to the MilTec and take extra care now flushing the chamber and bore with isopropyl alcohol.

Back to your question, I don’t see any signs of actual action movement in the chassis - which is good.

If this was an F class rig, it would be bedded as a minimum, more likely glued and screwed. But for range/PRS style use, I think it’s fine!

Interesting write up on PRS blog. Seems 50% of the top shooters skim bed their chassis. The reason given was not because they see accurate improvements or anything. It’s more they’re using it as an insurance policy in case they bang or drop the rifle during a strange at a match. But none seem to say it’s crucial to them. Again, f class is a whole different kettle of fish.

Had you not fitted the lug lock system/wedge?

[Catch-22]

1 minute ago, lapua said:

Had you not fitted the lug lock system/wedge?

Yes I had, just removed from pic at that time.

[Catch-22]

3 hours ago, Ronin said:

Thanks for the pics and explanation re the contamination 

 

the pics of the chassis show some witness marks (tang area and around forward action screw hole 

There are also witness marks on the action in similar areas 

There doesn’t need to be any movement under recoil to create these marks 

It highlights my point that even inlets thy replicate certain actions are not 100% contact and will cause stress in an action when torqued down due to elasticity of the materials and the high forces generated (even at 50 inch pounds) that’s enough to bend the action or pull it out of shape 

This will have an adverse reaction to accuracy 

How much is dependant on where and how much movement there is in the action and it’s effect on contact surfaces of bolt lug : abutments : barrel tenon 

An example - last week I bedded a HS Prevision stock (alloy v block design in let) to a rifle I built two years ago, the rifle was put in a used pre bedded stock (bedded to another action) bought post build by the client - it shot sub half Moa in that stock

I had some pictures back yesterday of groups shot with the rifle in the stock I bedded 

Single hole, consistently repeatable groups 

That demonstrates the importance of mating the action to the inlet with bedding 

This isn’t the first time such improvements  have been highlighted 

The rifle in question is for deer work - I’d recommend anyone with a comp gun give thought to this simple but effective improvement to their chassis based “system”

 

 

Thanks Andy.

I may well get the gun bedded at some point in the future.

Cheers