No more GM barrels in Mrods?

[FuzzyGrub]

John (FuzzyGrub) –You have tons of questions left.  At least 1 maybe 2…. 

Happy Shooting,
John

Thanks for commenting and clarifying for all us GTA members. 

I have to hold back and make sure my one question is a real "good" one! 

[BackStop]

John (FuzzyGrub) –You have tons of questions left.  At least 1 maybe 2…. 

Bob (rsterne) – Thanks for reaching out!  I try and get on there as much as I can but that is not always easy!  You post some awesome information and it is appreciated!

All – We are (and have been for a year or more) making our own .25 cal barrels.  I don’t know when exactly they went into production.  You can tell the difference between them by the crown.  The GM barrel has a deeper, almost recessed crown where the Crosman barrel has our standard target crown.  The quality of these barrels should be the same as our .22cal barrels. 

I cannot comment on what our barrel dimensions/parameters are.  I consider that something of a trade secret. 

I don’t know if GM sells barrels in small quantities but I know others do (Lothar, CZ and some others). 

Happy Shooting,
John

Thank you for that info John!   Can you give the twist rates for caliber?

Thanks...

[Airgun.Sniper]

Gives me the excuse to buy a new barrel now.

[rsterne]

Thanks for the reply, John.... I'm guessing we'll have to measure the twist rate (not a difficult thing to do)….

Anyone have a cleaning rod, jag and tight fitting patch available?.... Get to it, guys, it's not rocket science....

Bob

[FuzzyGrub]

Thanks for the reply, John.... I'm guessing we'll have to measure the twist rate (not a difficult thing to do)….

Anyone have a cleaning rod, jag and tight fitting patch available?.... Get to it, guys, it's not rocket science....

Bob

I actually made a half-hearted attempt, last night.  The mop style tip, was very hard to get past the choke.  It was too tight and the rod was not rotating the way it should.  It did fit the green mnt barrel and rotate they way it should, but didn't get the distance for one revolution.       When I get back from vacation, I'll post what I get for 2 GM barrels, and the crosman one.

[Jim Holmgren]

I have both the GM and the Crosman .25cal maruder barrels.

If I remember right the GM has 10 grooves and faster twist and the Crosman has 6 grooves and a slower twist rate.

[Jim Holmgren]

Does this mean Crossman makes the bulldog .357 barrel to?

[Crosman Engineer]

Jim - We still purchase the bulldog barrel.  Have you noticed an accuracy difference between the GM and Crosman barrel?

[Jim Holmgren]

Jim - We still purchase the bulldog barrel.  Have you noticed an accuracy difference between the GM and Crosman barrel?

Ok.

Sorry, I did only use the GM barrel mounted on a discovery which I no longer have.

However both of them seems to be well made ocularly...

[Cjs180]

I just bought mine about 2 months ago. Not sure what barrel it has but it shoots great for me. Mine has the synthetic stock.

Attached are 5 shots at 90 yards.  Without going through a lot of trouble, 90 yards is max I can shoot off my deck.

[KnifeMaker]

John (FuzzyGrub) –You have tons of questions left.  At least 1 maybe 2…. 

Bob (rsterne) – Thanks for reaching out!  I try and get on there as much as I can but that is not always easy!  You post some awesome information and it is appreciated!

All – We are (and have been for a year or more) making our own .25 cal barrels.  I don’t know when exactly they went into production.  You can tell the difference between them by the crown.  The GM barrel has a deeper, almost recessed crown where the Crosman barrel has our standard target crown.  The quality of these barrels should be the same as our .22cal barrels. 

I cannot comment on what our barrel dimensions/parameters are.  I consider that something of a trade secret. 

I don’t know if GM sells barrels in small quantities but I know others do (Lothar, CZ and some others). 

Happy Shooting,
John

A typical non answer from Crosman. It gets OLD!


all premium barrel makers, whether AG or PB "DO give full dimensions.


As do most air gun manufacturers.


the only logical reason Crosman won't give the same info other makers do,is that either thiers are vastly superior, or as this is obviously not the case,they are flat ashamed of their product.


Judging from their track record with the barrels in .22 for years, they have ever right to duck their heads in shame and avoid any info what so ever.


With that said, my maximus is very accurate with the new in house production.  One would think they would be proud enough to shout their accomplishment to the moon. Apparently they have no faith in their own product.


Worse yet, they seem totally oblivious to the fact than any one with a cleaning rod, and a mic can get the specs for themselves in minutes.


Apparently they think we are too stupid to complete such a task.


Someone is being less than intelligent regarding the matter. I wonder just who.


Not in the least impressed with Crosmean, and the way they treat the airgunning community.  the AG world is becoming very sophisticated.


I would like to see Crosman follow suite. Waiting!  But not holding my breath.


Knife

[YEMX]

Whelp, I'm gonna give GM a call on Monday then see if 1) They'll sell their .25 AG barrels to us, 2) Can we get them in other O.D.'s than .5", and or longer than 20", and if necessary 3) Put it in their heads to offer these barrels to the public. 

[screwwork]

I would love to have .25 cal GM barrel in .437 OD and longer than 20" for sure!
My .25 cal Prod would love it!

[K.O.]

I would love to have .25 cal GM barrel in .437 OD and longer than 20" for sure!
My .25 cal Prod would love it!

well not even if sleeving it to .5 or larger... (.4375 -.250) /2=.00625 way to thin of barrel walls... heck I want to sleeve the .4375 .22 Mrod barrels to fit the .25 Breech to have a stiffer  .22 barrel...

do agree it does feel like disrespect from any producer to not be allow to have the twist rate of barrels published... and some are published on the custom shop barrels... 1:20 for the .22 mrod crosman barrel and 1:16 for the .22 L.W.

[K.O.]

http://www.crosman.com/custom-shop/#

[screwwork]

My .25 cal Prod (AKA) mini-rod has a .25 cal GM barrel turned down to 7/16" to fit the Prod breach & my .25 cal Mag. It is a minute of squirrel all day long. If I could get a longer than 20" barrel in 7/16" .25 cal barrel it would most likely it would get CF sleaved flush to the breech. The MM HF .22 cal Mrod barrel in my Prod doesn't need to be sleeved either, they both rock although they are larger dia barrels.

[K.O.]

yeah I have two XL725 Barrels one is turned down to 7/16 for the Crosman Breech also and then 9/16 till the muzzle thread... used it for a long barrel 2100B  pump tube Hybrid 1325... shot Darn well with the FTT and Kings despite only being about 21 fpe...

plan on turning the other to .5"  for the Mrod ...  Hoping it will like cast...Could do a .25 Max/Disco with the  7/16 turned  barrel...

will eventually sleeve a Maxi .22 Barrel with some .5" O.D. .44 I.D. T6 6061 for the  .25 Mrod Breech for an about 25." .22 barrel...have an extra Max .22 barrel for the project... am thinking of just oring on the bolt and single shot... think would have to take a bit off the Breech end to get the transfer port to line up..

oh and sorry wall thickness for the 7/16 barrel is .09375...senior moment with the calc... in .22 it is about .11...

I still want a .5 O.D barrel nice to have a bit more  stiffness (.125 walls)... cube rule...

.09375 X .09375 X .09375=.000823

 and

.125 X .125 X .125=.00195

.00088 is 88 % of .00195...

 that means the .125" wall .25 auto .5" barrel is about 12% stiffer  than the .4375 .25 auto barrel ...given equal steel...

[Deckard1973]

http://www.crosman.com/custom-shop/#

What he said.

And, if you click on the question mark "Learn more about our barrels," it says the Crosman .22 barrel has 10 lands and groves, Twist ratio of 1:20, custom crown and it is choked.
Now, that is the Custom Shop.  Not sure if that translates to all their MRod barrels or not.

Me, I have a Gen I MRod.  I thought it was pretty accurate out of the box. 
Following Bob and NervousTriggers write ups, I polished the barrel. 
Now, I think it is crazy accurate.

[rsterne]

The stiffness of a rod is proportional to the 4th power of the diameter.... For a tube it is therefore proportional to (OD^4 - ID^4)…. For two .25 cal barrels , of the same material but different OD's, the ratio of stiffness is:

1/2" OD.... (0.5^4 - 0.25^4) = (0.0625-0.0039) = 0.0586
7/16" OD.... (0.4375^4 - 0.25^4) = (0.0366-0.0039) = 0.0327

Therefore the 1/2" OD barrel is (0.0586 / 0.0327) = 1.79.... ie the 1/2" OD barrel is 79% stiffer than the 7/16" OD barrel.... not 12%....

Bob

[screwwork]

The stiffness of a rod is proportional to the 4th power of the diameter.... For a tube it is therefore proportional to (OD^4 - ID^4)…. For two .25 cal barrels , of the same material but different OD's, the ratio of stiffness is:

1/2" OD.... (0.5^4 - 0.25^4) = (0.0625-0.0039) = 0.0586
7/16" OD.... (0.4375^4 - 0.25^4) = (0.0366-0.0039) = 0.0327

Therefore the 1/2" OD barrel is (0.0586 / 0.0327) = 1.79.... ie the 1/2" OD barrel is 79% stiffer than the 7/16" OD barrel.... not 12%....
Bob

Yea, what Bob said... LOL
Man Bob, when you say it that the .5" OD barrel is a lot stiffer than the .4375 OD barrel.
Thanks for putting it into perspective for me.