GTA
All Springer/NP/PCP Air Gun Discussion General => American/U.S. Air Gun Gates => Crosman-Benjamin Air Gun Gate => Topic started by: Psipumper on October 17, 2021, 10:40:53 PM
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After building my new 392 synthetic, the lever was ok until I tried 10 pumps. Folded under the pressure. I think the synthetic handle does not provide enough support allowing the lever to twist. Disappointed with this. I have a billet Mac1 lever to use and should solve my problem. I hope , the brass tube was bent slightly . May can try to straighten the tube to usable.
Only billet for me from now on.
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The lever had some pressure on it because the 392 was built high performance and at 8 pumps was 810 fps. If it got to 10 , it should have made 875 fps.
Something flimsy with the synthetic stock. I have pumped to higher pressures hundreds of times with the wood versions with no issues.
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Charles,
I had the same piroblem with 2 in a row of the 392s version.
I was using 10 pumps as it says it’s rated and both pump arms twisted... one of them in less than 30 shots.
I finally called crosman about the problem and was told by the guy I talked to that the 10 pumps is a misprint in the manual and that it’s really only rated for 8 pumps! :o
Says he’s made crosman aware of this?
It definitely needs bracing if going for 10 pumps with the original linkage, as the plastic posts they use for linkage support don”t Keep it from twisting.
Lol, you won’t twist that Mac1 arm and linkage.
Don’t know how those plastic posts are going to hold though?
I’m going to order a Mac1 linkage for mine too... was supposed to have already done that.
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Charles,
I had the same piroblem with 2 in a row of the 392s version.
I was using 10 pumps as it says it’s rated and both pump arms twisted... one of them in less than 30 shots.
I finally called crosman about the problem and was told by the guy I talked to that the 10 pumps is a misprint in the manual and that it’s really only rated for 8 pumps! :o
Says he’s made crosman aware of this?
It definitely needs bracing if going for 10 pumps with the original linkage, as the plastic posts they use for linkage support don”t Keep it from twisting.
Lol, you won’t twist that Mac1 arm and linkage.
Don’t know how those plastic posts are going to hold though?
I’m going to order a Mac1 linkage for mine too... was supposed to have already done that.
Buddy, I did try to reinforce the lever because of your problems with yours. I welded a piece to make it solid at the bolts that hold the plastic handle.
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On the bright side, I built this wood carbon copy of it for a friend. Good late model (2018) . Slim stock . Weighs 7 pounds dressed out. Super smooth pumping but wondering about that stock linkage now.
I will recommend he upgrade it. I was foolish to build it without.
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It might hold up to the extra pump pressure since the groove in the bottom of the wood forearm braces the arm.
May get premature wear where the linkage attaches though?
Probably a good idea to upgrade to a Mac1 billet arm and linkage for longevity.
I’ll eventually have all my 392 and 397 rifles swapped over to Mac1 billets just for that reason.
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I didn't realize how flimsy the synthetic stock arm was, looks hollow, till I saw the picture. Really needs that Mac1 pump lever. The wood stocks support the stock lever pretty good with the fit in the narrow slot. Although I never had the original one bend in wood, I have this Mac1 Billet lever on this 392. You can see the difference vs the above bent one. (http://)
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Mine were both in stock form... the first bent the arm in just under 100 shots. PA sent a replacement and it bent in less than 30 shots.
I’m surprised there have’nt been more reports of bent arms. I was using the full 10 pumps 90% of the time on both.
I do like the synthetic stock and the all weather aspect of it and the fact it’s a good design for scope use.
I think they would hold up to max pumps if crosman would use a solid piece of synthetic with a trench in it for the full length of the billet arm instead of the three small “posts” spaced out they’re using now.
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Crosman has probably had hundreds returned with this issue. The design of the synthetic is an engineering failure to realize the strength added by the close fitting slot that resisted torsional loads on the lever.
They can say the manual was misprinted or we may have had a batch of weak levers.
Surprising they didn’t test it to destruction before releasing it on the public.
I don’t have anything against the looks of the synthetic 392 but it is 8 ounces heavier than the wood one. With the needed billet lever, that will add some more weight and cost to it.
They really should go back to the wood version instead of discontinuing it.
I hope they learned something they can use to improve the 362 at least.
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I would love to see the wood stock version back.
Would also hope they improve the support of the lever on the synthetic model.
Seems a simple redesign for full length support of the lever arm would be all that’s needed?
I would truly hate to see them discontinue the 392 and 397 all together :o.
BTW, I was also told by the crosman rep. I talked to about this problem to hold the pump arm in the center on the synthetic model when pumping.... that kind of defeats the purpose of an extended pump arm does’nt it? :-\
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I would love to see the wood stock version back.
Would also hope they improve the support of the lever on the synthetic model.
Seems a simple redesign for full length support of the lever arm would be all that’s needed?
I would truly hate to see them discontinue the 392 and 397 all together :o.
BTW, I was also told by the crosman rep. I talked to about this problem to hold the pump arm in the center on the synthetic model when pumping.... that kind of defeats the purpose of an extended pump arm does’nt it? :-\
The new stock has been out a couple years now without improvements. I don’t know what would be involved to change the mold to a solid slot. $30,000 or more.
I wouldn’t want to see it discontinued altogether either. I would like to see the wood version come back as the 392 classic and a lightweight carbon fiber stock edition for a hundred dollars more.
I found my billet lever and weighed it , four ounces heavier than stock one.
I will get back to repairing it soon. Should be a nice all weather durable hunter then.
Crosman should also adjust the bore size to 5.50 while their at it.
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" I don’t know what would be involved to change the mold to a solid slot. $30,000 or more.
I wouldn’t want to see it discontinued altogether either. I would like to see the wood version come back as the 392 classic and a lightweight carbon fiber stock edition for a hundred dollars more."
ITs not just the mold. now youve got more packaging to have made and keep around, either another line to assemble the other stocks/time share a line to build them, more inventory to warehouse, more money tied up in inventory, and the big one.... convincing existing corporate customers (Walmart, BassPro etc) to carry, stock and shelve 6 more products (synth, wood classic and CF in two calibers).
Seems to me this is an EXECELLENT market opportunity for someone to make wood stocks in a variety of styles for this gun. Personally Id love a DaveG styled thumbhole carved from a colored laminate.....
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I would like to see Boyd's make a nice walnut stock set for the 392.
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Makes me glad I got a late model wood version.... ;)
Bob
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Crosman should also adjust the bore size to 5.50 while their at it.
So the 392 bores still oversized?
I have 101s, 312s, and 342s that shoot better than the 392P and 2 392PAs I've owned.
I hope if I keep trying I'll get a great one. Weird thing though, is the 101 bores also seem loose but they still make tighter groups.
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What kind of muzzle energy levels are people seeing with Mac 1 steroid builds? Is the steroid build "DIY friendly"? I've looked at the 392s off and on for over a year now. Could a steroid treated 392s fire a cast 20 grain pellet above 650 FPS?
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Crosman should also adjust the bore size to 5.50 while their at it.
So the 392 bores still oversized?
I have 101s, 312s, and 342s that shoot better than the 392P and 2 392PAs I've owned.
I hope if I keep trying I'll get a great one. Weird thing though, is the 101 bores also seem loose but they still make tighter groups.
I measure them to be about 5.58mm . I don’t have any older models to measure and haven’t seen any posted measurements from anyone.
I don’t think the accuracy of a 312 or Sheridan would be automatically better.
The wooden stock 392PA shown above is the most accurate I have messed with.
Maybe it could be matched in accuracy by a scoped vintage rifle but I couldn’t see any room to improve.
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What kind of muzzle energy levels are people seeing with Mac 1 steroid builds? Is the steroid build "DIY friendly"? I've looked at the 392s off and on for over a year now. Could a steroid treated 392s fire a cast 20 grain pellet above 650 FPS?
How about 760 FPS. and about 25.6 ft. lbs with a 20 gr. NOE cast pellet?
Of course that’s on 14 pumps from my 392pa steroid.
8 pumps gives 645 FPS and 18.4 ft. lbs. with the same pellet.
6 pumps is 588.9 FPS. and 15.4 ft. lbs.
Heavier pellets up to about 30 gr. produce even more ft. lbs.
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What kind of muzzle energy levels are people seeing with Mac 1 steroid builds? Is the steroid build "DIY friendly"? I've looked at the 392s off and on for over a year now. Could a steroid treated 392s fire a cast 20 grain pellet above 650 FPS?
How about 760 FPS. and about 25.6 ft. lbs with a 20 gr. NOE cast pellet?
Of course that’s on 14 pumps from my 392pa steroid.
8 pumps gives 645 FPS and 18.4 ft. lbs. with the same pellet.
6 pumps is 588.9 FPS. and 15.4 ft. lbs.
Heavier pellets up to about 30 gr. produce even more ft. lbs.
Is it true that Tim won't work on the late model 392 synthetic? I saw an older thread, circa 2016 (?) saying that he won't work on a 392PA, which has a cartridge valve.
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Mr. Tim WILL work on the pa as he just did one for me last year.
I talked to him fairly recently and was told he had done at least one of the new synthetic 392s someone had sent him.
Don”t know what he did( if anything) about stiffening the posts the billet arm lays in.
Maybe all it needs is his billet arm?
Think i’m going to send my 392s to him for steroiding, or maybe just order a valve and billet arm and lever from him.
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Mr. Tim WILL work on the pa as he just did one for me last year.
I talked to him fairly recently and was told he had done at least one of the new synthetic 392s someone had sent him.
Don”t know what he did( if anything) about stiffening the posts the billet arm lays in.
Maybe all it needs is his billet arm?
Think i’m going to send my 392s to him for steroiding, or maybe just order a valve and billet arm and lever from him.
Is the steroid treatment possible as a DIY procedure, or does it require the wizard's hands? 25 FPE out of a pumper sounds awesome.
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Mr. Tim WILL work on the pa as he just did one for me last year.
I talked to him fairly recently and was told he had done at least one of the new synthetic 392s someone had sent him.
Don”t know what he did( if anything) about stiffening the posts the billet arm lays in.
Maybe all it needs is his billet arm?
Think i’m going to send my 392s to him for steroiding, or maybe just order a valve and billet arm and lever from him.
Is the steroid treatment possible as a DIY procedure, or does it require the wizard's hands? 25 FPE out of a pumper sounds awesome.
A lot of the parts can be bought from Mac1 and installed yourself.
The way I understood Mr. Tim from talking to him several times though, to get the ultimate from the steroid treatment, there is hands on custom work he has to do himself to it in the end to get the full steroid benefit from it.
That “extra” benefit is significant. ;)
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this was really hard to make , be nice if someone made something similar for the 392 .. solid piece of steel cut and slotted to size, almost indestructible.
(https://live.staticflickr.com/65535/51371896691_0008c5ecff_z.jpg) (https://flic.kr/p/2mgyp7K)20210811_124827 (https://flic.kr/p/2mgyp7K) by murphyrobert9 (https://www.flickr.com/photos/56743574@N07/), on Flickr
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Now that is solid built. No doubt added cost, but worth it for longevity!