Gunsmithing Surgeon Action = No muzzle jump

[mdesign]

I noticed this claim on Surgeon's web site, anyone with experience to vouch for this? Seems like a pretty big claim or is this something other than muzzle jump caused by recoil?

<span style="color: #3366FF">The ¼” thick integral recoil lug gives a 37% increase in receiver threads over a Rem 700. This increase in thread contact between the barrel and action along with the recoil lug being made into the action eliminates vertical muzzle flip that is normally seen in actions that have a recoil lug sandwiched between the barrel and the action.</span>

 

[427Cobra]

Re: Surgeon Action = No muzzle jump

I think it helps strengthen the action, but in my experience muzzle jump is a product of poor shooting technique, I'll let ya know next year for sure when my Surgeon 260 is together.

 

[Dustin Morris]

Re: Surgeon Action = No muzzle jump

"Eliminate" is a very strong word.... I think "significantly reduce" would be more fitting.

 

[ssgp2]

Re: Surgeon Action = No muzzle jump

Muzzle flip does not mean recoil.
They are claiming a stiffer action/barrel assembly, not a reduction in recoil

 

[JJones75]

Re: Surgeon Action = No muzzle jump

i don't see how a rifles action desgine is going to do anything to influance muzzel jump , as it was said before , poor shooting form is a big reason along with weapon weight , balance and stock desgine

 

[bohem]

Re: Surgeon Action = No muzzle jump

Nothing with the standard setups can eliminate muzzle flip. There's no such thing as a truly rigid structure.

Their configuration can reduce it, maybe even significantly, but from an engineering point of view I'm going to wave the BS flag.

There's a loading moment that is reacted by the recoil lug through bending the tenon area. If you make that joint stronger, the bending deflection (seen as muzzle flip) is reduced.

 

[treebasher]

Re: Surgeon Action = No muzzle jump

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bohem</div><div class="ubbcode-body">Nothing with the standard setups can eliminate muzzle flip. There's no such thing as a truly rigid structure.

Their configuration can reduce it, maybe even significantly, but from an engineering point of view I'm going to wave the BS flag.

There's a loading moment that is reacted by the recoil lug through bending the tenon area. If you make that joint stronger, the bending deflection (seen as muzzle flip) is reduced.

</div></div>

+1

 

[300sniper]

Re: Surgeon Action = No muzzle jump

the only thing i can see is the affective unsupported barrel length is shorter than one with a separate recoil lug/shorter threaded receiver ring. if we are talking about .25" shorter of unsupported barrel length, i honestly can't see anyone noticing a difference without some serious testing equipment. i would be extremely surprised if someone could prove there is a difference on the target simply because of this.

now i do think there are some great benefits from a one piece recoil lug/receiver combo from an installer's prospective.

 

[mdesign]

Re: Surgeon Action = No muzzle jump

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body">...if we are talking about .25" shorter of unsupported barrel length, i honestly can't see anyone noticing a difference without some serious testing equipment. .... </div></div>

I thought the same thing. I was thinking about buying a Surgeon and still am as I think they are a great action. I have Stiller and Remington, they are good as well but if you have muzzle flip because you have a poor barrel connection I would think you have other issues as well.

I like the integral scope mount, I can see why that would make an action stiffer and benefit accuracy. Just seemed like a pretty big claim to me.

 

[stiller]

Re: Surgeon Action = No muzzle jump

My belief is that he is referring to some shots going vertical due to motion in the joint or lack of stiffness. Basically causing larger groups due to inconsistent shot to shot motion in the barrel/action joint. If this is his statement, in my engineering opinion, that is complete bullshit. Most joints carry about 4 to 5 threads worth of load. If the joint is tightened correctly, there is no motion in the threads and preload is never lost. Back in the late 90's I performed an analysis on the joint and determined approximately 100 ft-lbs of torque on a 16 to 18 tpi thread would never unload under a 100,000 psi magnum boltface load under the industry standard assumptions made on the threads.

I have been shooting benchrest for about 10 years now. I have cut back many barrels and have run short threads in them when I have. I have never seen any difference in accuracy due to this. Benchrest actions have just about any configuration you can imagine and they all seem to work fine when tightened, and most br shooters dont even tighten them that much.

I think that is a very brazen statement to make without any data to back it up. If that is the case, most every target rifle in the world built on a Reminton style tenon or with a recoil lug will shoot like crap compared to a Surgeon. Last time I looked, I didnt see the equipment list covered over by them.

 

[bohem]

Re: Surgeon Action = No muzzle jump

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: stiller</div><div class="ubbcode-body">My belief is that he is referring to some shots going vertical due to motion in the joint or lack of stiffness. Basically causing larger groups due to inconsistent shot to shot motion in the barrel/action joint. If this is his statement, in my engineering opinion, that is complete bullshit. Most joints carry about 4 to 5 threads worth of load. If the joint is tightened correctly, there is no motion in the threads and preload is never lost. Back in the late 90's I performed an analysis on the joint and determined approximately 100 ft-lbs of torque on a 16 to 18 tpi thread would never unload under a 100,000 psi magnum boltface load under the industry standard assumptions made on the threads.

I have been shooting benchrest for about 10 years now. I have cut back many barrels and have run short threads in them when I have. I have never seen any difference in accuracy due to this. Benchrest actions have just about any configuration you can imagine and they all seem to work fine when tightened, and most br shooters dont even tighten them that much.

I think that is a very brazen statement to make without any data to back it up. If that is the case, most every target rifle in the world built on a Reminton style tenon or with a recoil lug will shoot like crap compared to a Surgeon. Last time I looked, I didnt see the equipment list covered over by them. </div></div>

Exactly on with joint analyses that I've done for race car applications. The minimum you absolutely must have is 3 threads of engagement and anything more than 5 is generally a waste of materials.

 

[monteboy84]

Re: Surgeon Action = No muzzle jump

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: stiller</div><div class="ubbcode-body">I think that is a very brazen statement to make without any data to back it up. If that is the case, most every target rifle in the world built on a Reminton style tenon or with a recoil lug will shoot like crap compared to a Surgeon. Last time I looked, I didnt see the equipment list covered over by them. </div></div>

Agreed. Even the science behind the statement is flawed, muzzle flip as a matter of physics, is caused by the height of the bore in relation to the height of the point where the stock contacts the shooters shoulder. There are other factors which can influence this such as rifle weight, muzzle devices, pistol grip-style stocks, etc, but the general rule still applies. It's a simple lever system where the butstock contacting the shooter's shoulder is the pivot point, the force applied is centered about the bore, and the opposing force is the weight of the rifle, pulling downward at the center of gravity. It has nothing to do with the barrel's thread engagement....

Perhaps an integral lug will reduce barrel whip, but claiming it will eliminate muzzle flip is absurd.

-matt

 

[300sniper]

Re: Surgeon Action = No muzzle jump

and from my non-engineering, garage hack point of view, i still think that a larger outer diameter of the barrel shoulder would have a greater affect on the stiffness of the joint than a longer threaded tenon.

 

[preston pritchett]

Re: Surgeon Action = No muzzle jump

Guys
I am going to have to agree and disagree with the BS flag. What started out as a quote from Harold Vaughn book “Rifle Accuracy Facts” over the years has been cut and pasted to what you see today. We shouldn’t have used the word eliminate we should have said greatly reduced. The post started out about our comment of muzzle flip and was changed to muzzle jump, which in my opinion is a totally different subject.

As for Harold Vaughn, he was a leading research scientist and a Supervisor in the Aeroballistics Division Sandia National Laboratories. He is considered the “grandfather” of the aero ballistics/flight mechanics technology base for nuclear ordnance at SNL. There are 3 pages in the front of his book as to his achievements and if I am going to lean towards someone being right as of now I will put my money on him.

You can take a verse out of any book and make that book say anything you want. In my opinion you need to read the chapter or even the whole book before you can say with a better understanding of what they are trying to say.

On page 42 he starts talking about Receiver Ring Moment I am not going to type the multiple pages on this but in the end it is my understanding because of the window cut out and the bottom of the receiver cut out on most actions you have more vertical (it is actually from 7:00 to 1:00) movement due to the weakness of the action in a vertical plane vs. the horizontal plane.
He greatly reduces this problem by silver soldering a one pc scope rail on the top of his action. (pg 59 Receiver Modifications) We didn’t completely cure this problem but we greatly reduced it when we made the scope rail and the action 1 pc.


On page 46 he talks about the affects of recoil on the recoil lug.
“ When the rifle is fired there is a net recoil force action on the rifle action that is equal to the force action of the base of the bullet, which is about 3,000 pounds at the peak chamber pressure of 53,000 psi. The force acting on the bullet was shown in figure 2-24. This force is transmitted to the stock by the recoil lug on the bottom of the rifle action. Since there must be an equal and opposite reaction to any force, the stock exerts and equal force on the recoil lug in the opposite, or forward direction. This force results in a recoil moment being exerted on the forward receiver ring tending to drive the muzzle in an upward direction. He cured this in his test fixture by placing a recoil isolator between his recoil lug and his test fixture. We feel we greatly reduced this when we make it all one pc.

He said on page 74 that he done enough measurements on the unmodified standard rifle to convince him that the horizontal motion of the muzzle is about 1/3 of that in the vertical plane.

On page 103 he starts talking about barrel-receiver threaded joint motion. The first 2 sentences in the book said. “It would hardly seem possible that the threaded barrel joint could move, causing the barrel to point in a slightly different direction after a shot is fired. But, that is exactly what happens, and barrel joint motion can cause large flyers (i.e., one inch or more in a group)”. He goes on and at the bottom of the paragraph said. “Under some temperature conditions, such as rapid fire, it is possible for the joint to be completely unloaded or loose when the gun is fired.” He goes on to talking about barrel joint axial preload measurements. Multiple tests yield strengths, loading using lube between the mating surfaces. Trying different thread designs etc. He also has a graft on pg 114 about the average percentage load of Standard National Form V threads. 1st thread holds 36%, 2nd 23%, 3rd 15%, 4th 9%, 5th 6%, 6th 4%, 7th 3%, 8th 2%, etc. I will be the first one to admit that the first threads hold the most but on my gun and the guns we build I want as many threads as I can get.

So after reading your post and comments I am going to have to agree with you guys. We did not eliminate the vertical. But I will say we (the crew at Surgeon) greatly reduced it and feel I am not blowing smoke when I say it. We will change the wording on our website from eliminate too significantly reduced to give a truer statement.

Thanks for keeping us in line.

 

[JJones75]

Re: Surgeon Action = No muzzle jump

Mr Pritchett , not to hijack the thread but I was wondering if you have ever dolt any with "Spiralock" threads , they are said to be used mostly in the areospace industry , I work in this field and have never more have any of our machinest seen them.
They are supposed to distribute the load accross ALL of the threads.

And what you posted makes the initial comment make alot more sense now

 

[mdesign]

Re: Surgeon Action = No muzzle jump

Preston, thanks for your clarification. Wasn't trying to cause a problem but am thinking of buying an action for a project and was off researching the different possibilities when I noticed the statement.

I own and have read Harolds book and often wondered if the concepts put forth from his testing would really transfer into the super accurate hunting rifle in the real world. Vertical is a very real happening that most shooters deal with at one time or another.

Per an earlier comment, Do you have any thoughts regarding the diameter of the barrel as it relates to the dia of the action? Does a larger shoulder give less of a moment for the joint to flex, thus stiffening it?

A free body diagram suggests that the basic mechanics would be stiffer but not sure if it would translate into improved group size.

 

[preston pritchett]

Re: Surgeon Action = No muzzle jump

JJones
A guy called the shop a few years back and said his name was Robert Gradous http://www.gradousrifles.com/ he talked to Matt and asked him how we built rifles and after talking to him he ask him if he wanted to know how to build rifles better. A few days later after driving for days he showed up and at first when I listened to him I thought BS. Then the more I listened the more I realized that he was ahead of us. I am not the smartest guy in the world but I know I got 2 eyes 2 ears and 1 mouth and therefore I need to look and listen about 4 times more than I talk. Long story short Robert became and is a good friend. When he left he ask us one favor. And that was to keep what he told us to ourselves. I have tried to keep that promise. A while back he posted about teaching guys to build rifles for a price. The price is about what it would cost you to buy a rifle from one of the top smiths. You spend a few days in his shop and you hands on build your own rifle. Not to dodge your question but to try to keep my word to a friend. I am going to have to plead the 5th. My advice is to call him or better yet talk him into putting on a class for you.
Thanks

 

[preston pritchett]

Re: Surgeon Action = No muzzle jump

Mdesign
If you will notice when people test ammo they are mainly testing for vertical. Mostly because the wind is the main horizontal problem.
I would have to agree with you on your opinion on the larger barrel diameter. It will cost a few $ more but shooting is a mental game. Lets say worst case it don’t help at all mechanically. If I think it helps it is a big gain. To give you my opinion, on our new long 1pc actions I have a 1.350 barrel coming for it to build a 300WM. Not only do I have a 1.350 barrel coming some of the guys I shoot with have them coming for there guns also so I just hopped on the band wagon. The added weight is not going to hurt us because at most of these matches it is not like your walking 5 miles with it. And a 300WM shooting the 210s I am thinking I might like the lower recoil due to the weight. If you don’t want the extra weight have them contour it to your specs. I do know the top 2 guns that done a test at 1500m at AMU 338LM. One of them had a 1.350 barrel with 1-1/8 x 16 threads. And if your going to spend that much money on a custom rifle and even think it might help it would be worth the couple extra $ to find out.
And I was told a few minutes ago on the post at Terry Cross and Jim Clark match that 8 of the top 10 were shooting Surgeons. So we must be doing something right. And like Terry told me a couple years ago. The only thing he knew for sure was that in a few years he would be building a better rifle than what he was building at that time. I do know that our actions are getting better all the time. Once you think you have something all figured out you find out you wasn’t as smart as you thought you was and here you go again.
Thanks
.

 

[psinclair]

Re: Surgeon Action = No muzzle jump

+1 Preston....I've never seen one of your bolt handles break off either.

 

[jasonk]

Re: Surgeon Action = No muzzle jump

preston, I can't comment on the barrel flip, rise, whatever.

What I will comment on is that I took delivery of my new Surgeon today. Not only is the rifle smokin' hot, but I truly appreciate the level of detail your shop has. The AICS mags I had modified and the bolt was resealed in plastic bags, the gun was tucked nicely in a sock in the hard case, the case was sealed...and I mean sealed with a cable to prevent tampering (I bled getting into it, but that's another story).

Anyway, given the attention to detail on the smallest of things I can only imagine the detail that goes into the parts that count.

Thank you so much for what's already my favorite rifle to date and I will soon post a range report complete with some sexy gun porn pictures!

Jason

 

[mdesign]

Re: Surgeon Action = No muzzle jump

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: preston pritchett</div><div class="ubbcode-body">....And I was told a few minutes ago on the post at Terry Cross and Jim Clark match that 8 of the top 10 were shooting Surgeons. So we must be doing something right.
</div></div>

Which is why I was looking on your website! I've heard some good things regarding the stiffness of your actions and the quality of the machine work.

 

[preston pritchett]

Re: Surgeon Action = No muzzle jump

Jason
Thanks

MD
Thanks

PGS
I did see one break off cause Matt put a bolt in the vice and took a 3 ft cheeter pipe to the handle and twisted this way and that untill he broke it off. So I can't say that but I was watching and I know it was not easy for him. bolt looked like a pretzel when he was thru

 

[snommittj]

Re: Surgeon Action = No muzzle jump

I don't have a clue about all of the physics that are going on when a rifle is fired, but I do know that alot of people in the tactical rifle business are grateful for the Surgeon/Gradous relationship. They have figured out and put together a hell of a good product that shooters can count on. Thanks guys.

 

[bohem]

Re: Surgeon Action = No muzzle jump

Preston, thanks for clarifying the statement on the website. I agree that vertical rise from recoil reaction around the stock and shooter is a totally different topic, which is why I've not addressed it.

There's some very detailed things involved with mating a load bearing joint like this, and it's a fine detail level work that allows for the truly analytical solutions to be accurate.

Thank you for addressing the comments here and I hope my comments haven't offended you/your company. Discussions like this I really enjoy, as I really enjoyed Mr. Vaughn's book when I read it. For anyone who wants to really understand this passion it's practically a necessity to read.

 

[psinclair]

Re: Surgeon Action = No muzzle jump

Preston, I still have the rifle you put together for me.. it was from the first run of actions....its still the most accurate rifle I own. I have killed over 700 coyotes with it.

A 3 foot cheater on a Surgeon bolt handle makes me cringe...UHHG!!!

 

[Clark]

Re: Surgeon Action = No muzzle jump

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: preston pritchett</div><div class="ubbcode-body">
On page 46 he talks about the affects of recoil on the recoil lug.
“ When the rifle is fired there is a net recoil force action on the rifle action that is equal to the force action of the base of the bullet, which is about 3,000 pounds at the peak chamber pressure of 53,000 psi. The force acting on the bullet was shown in figure 2-24. This force is transmitted to the stock by the recoil lug on the bottom of the rifle action. Since there must be an equal and opposite reaction to any force, the stock exerts and equal force on the recoil lug in the opposite, or forward direction. This force results in a recoil moment being exerted on the forward receiver ring tending to drive the muzzle in an upward direction.<span style="color: #FF0000">" </span>He cured this in his test fixture by placing a recoil isolator between his recoil lug and his test fixture. We feel we greatly reduced this when we make it all one pc.


</div></div>

I inserted, in red, what I believe to be your missing end quote.

The idea that a free recoiling symmetrical barrel [until bullet escapement] in the axial direction will not flip is easy to see. The idea that if it gets connected to an asymmetrical stock with some drop at the heel will cause muzzle flip is also easy to see.

But making the recoil lug one piece with the receiver is likely to make a lower compliance connection that increases muzzle rise. I recognize that is secondary to the effective length, width, and thickness of the lug as well as Modulus of Elasticity of the lug material.

I am not questioning the benefits of an integral recoil lug.

I am questioning your post associating integral lug with increased isolation.

That is, if you meant one piece reduces muzzle rise.
If you meant that one piece reduces isolation, never mind.

My previous post on SH on Vaughn's rem700 thread mod