HW97KL sudden power lost

[max115]

Just wondering if any of you have experienced with the sudden power lost/gain with your new AG.

This morning my new HW97KL .177 (24 days old) was shooting consistently for a few days now of 997fps using H&N FTT 8.64gr. This evening I took a shot at the same paper target and the POI was two dots lower. I thought I had pulled or screwed up with my follow thru so I took 4 more shots. All the shots went thru the same hole but 2 dots lower than my POA. I quickly chrony it and to my horror, the avg was 830fps (lost 167fps in 12 hours). The gun was put away safely in its case.

I am puzzled with this sudden lost of power. Even if the gun is bedding in after 600 pellets or less, I wouldn't think it would loose 167fps without warning.

I will need to open it up and examine the seal and spring for damage. Has this sort of thing happen to you?

any thoughts or comments would be greatly appreciated. I was so pleased with how this AG is performing thus far till this happened. :cry:

thanks.

[JimL911]

I would say that you have finally burned off the factory lube that was giving you 997 fps. In .177 the 97 is a 13-14 fpe gun which is what you are getting(13.22). 997 with 8.64 grain pellets is over 19 fpe.

[max115]

Hi Jim,

I would hope so that was the case of lube being burn off.  But I had stripped the factory lube and do the clean, debur, moly in the very beginning.  So I can't say it was the factory lube issue.  However, it might have been something else.

In any event, I will need to open it up and examine the internal.

thanks for chiming in.

[Mark 611]

the breech seals in these rifles from the factory are not very good and have a very short life span all sliding compression tube rifles, if you don't keep the breech slightly open to keep the seal from being under consistent pressure it will smash out in short order and will no longer seal properly! 1 of the Vortek products I would recommend if Tom is still making them like he use to? is the breech seal he makes for the HW95 R9 {etc} rifles not the OEM ones they are very hard and work quite well in the 97/77 breeches, I had very good luck when I used them in my 97's, also what I do is use an old piston seal with the hole in the center of them and put it between the compression tube and the barrel lead in so the breech seal isn't under compression all the time when not in use  yes the cocking handle will not closed all the way but it will prolong your seal life 10 fold my 2ct

[max115]

thank you Mark for the breech seal suggestion.  I will be ordering some from JM, including a tune kit, seals, buttons, and lube. 

Is 830 fps with H&N FTT 8.64gr normal for this type of AG?

thanks.

[Cloud 9]

My HW97k shoots H&N FTT 8.64gr @ 850fps consistently. Has a Vortek kit and about 2000 shots so far. Mine never shot as fast as yours even right after the lube. & tune.

[mtsheron70]

I would say maybe a nicked piston seal could be your culprit.  You said you broke the gun down to wipe down factory lube and re-moly.  You may have accidently nicked the seal going back in.  Just a thought.

[Mark 611]

the JM breech seals are to soft, at least the ones he makes, their to soft for the 97, they won't take being closed all the time that's my experience using them but they work good in the break barrel rifles JMO

[max115]

Here is a summary and update with my HW97KL.  Thank you all for chiming in and offering your thoughts and advice.  And reading my posts.

when I first got the AG, I did 10 chrony shots and recorded 888 fps with JSB Exact 7.87gr.

the gun was twangy and shots were not as smooth. Dieseling was present because I could see and smell it.

I then took it apart and cleaned out the internal removing the factory lube, some clumps of grease were formed at the trigger catch and the other area. The factory lube wasn't too bad but I replaced it with Moly paste and debur anything inside that were sharp from factory condition. I also fitted a thin sleeve between the spring and piston to help with the shot cycle and remove some of the twang sound. It seems to do the job.

I continue to shoot the gun after that and found the gun was getting smoother and better. I didn't chrony since day 1(Dec.11) because it wouldn't make any difference in knowing what the power would be during this initial break-in period. Then one day I found the POI was way higher than my last session so I chrony it the second time(Dec.21). the gun was shooting at 1032fps avg with the 7.87gr, an increase of 144fps with the lighter pellets. By now I had ordered some H&N FTT 8.64gr to try out and it was 977fps.

I was adviced not to use light pellets so I stop and only shot the 8.64gr. on Dec.23 3rd chrony - 915fps. shot cycle getting better and accuracy was better also.

Jan.1, I polished both the piston and spring chamber to mirror finish, chrony - 980fps. So power gone back up again, and accuracy remained consistent. I was beginning to cut playing cards in halves and cutting strings quite easily at 13 yards indoor. for the next 3 days I was shooting everyday maybe 20-50 shots per session. By now the gun was just deadly accurate and I was extremely pleased until the "power lost" occurred last night.

Jan.5. I opened it up and examined the internal. nothing was broken nor looked out of place. some moly paste got in front of the piston seal, which is normal. I can't really tell if the breech seal is damaged or not. Piston seal has no nicks or cuts. chrony - 837fps with 8.64gr H&N, and 881fps with JSB 7.87gr which is similar to the initial reading when I got it new.

My own diagnostic: maybe this gun has bedded in with the seal and "break-in" period and it only runs in the power range of 840fps with 8.64gr and 880fps with 7.87gr.

I am just gonna continue to shot it and see what happens. either way, it was fun to have shot the gun over 1000fps and 19 ft.lb!

I guess as long as the AG can continue to consistently cut cards and hitting where I aim, it is all good regardless of its power output. I can always get a JM kit to compare.

cheers.

[Mark 611]

those are normal velocity's as long as your extreme spread and the standard deviation aren't to crazy I'd say your good JMO

[mtsheron70]

I agree with Mark.  Those numbers in velocity as compared to pellet weight seem right on.  You have to remember a .177 HW97 by the manufacturer states 930 fps I believe but that is with the lightest thing they can find I would almost bet.  I think manufacturers should be required to test shoot a mid range weighted pellet and note which it was for the test and for noting by retailers.  That way you have a baseline to go on. 

Just my 2 cents and way I would say it should be regulated or done to give more actual number expectations for consumers.

My .22 caliber HW97k right off the top of my head shoots 14.72 grain Beeman FTS copper plated at if memory serves me high 700's I think.  Been so long since I looked at my data I could be wrong.  But I did the same as you, broke the gun down and polished the piston and internal chamber and did a Vortek drop in tune kit 17-18ft. lb version.  This thing is deadly accurate out to 35 yards and putting out around 16 ft/lbs. give maybe a little.  Once again my data escapes my mind.

But you look like your on course.  Enjoy that fine German underlever!

[max115]

thanks Mark & Mts.

well, I am lost for words today.  What they said about "when it rains, it pours?"

I have accepted the fact that my HW97KL is running at 880fps, but now my brand new Hawke Airmax scope is toasted the day after.

My POI was an inch lower than before and I never touch the elevation since I have zeroed it.  So I adjusted the elevation to raise the POI, and nothing would change.  I continued to turn it until the I have reach the max.  POI still remained low.  So the inner tube is not moving up when I am making the adjustments.  I turned it down to check and POI would go down with the adjustment.  The scope just wouldn't go up to where it was for my zeroed range of 13yards.

Oh....so frustrated.  And this was a new replacement scope that I got from AGS.  The first one couldn't even hold zeros.  Are the Hawke scopes really bad?  I have such high hopes with this brand and all the reviews that I have read support their reputation.

I am having a second thought now.  Anyway, I had to email AGS and explained what I found with this new scope.  I am hoping that they would just help me resolve this issue without too much resistance to replace.  I have asked to exchange and pay for the extra for a Varmint.  Hopefully 3 times is a charm.

man...this AG thing is so stressful or may be just me running into bad luck this new year.

[Mark 611]

Hawke, has had issues with their optics, I understand how you feel I personally have no experience with them, I use the Leapers scopes and have had pretty good luck with them, yes I've had some of them fail as well but they seem to hold up pretty well if you get a good 1 I also have used some Bushnell scopes, not the super cheap ones, if you look @ their 4200 Elite series {etc} they are AG rated and are pretty tuff scopes IMO, my 2ct

[palonej]

Hey Max. I have a bunch of Hawke scopes and love them!!
I had a problem or 2 and called Mike at Hawke. You pay shipping to them, cost me about $8, and they'll send you a new one no questions asked. Usually takes a few days. Great deal!!
Mike (877) 429-5347.

[mtsheron70]

thanks Mark & Mts.

well, I am lost for words today.  What they said about "when it rains, it pours?"

I have accepted the fact that my HW97KL is running at 880fps, but now my brand new Hawke Airmax scope is toasted the day after.

My POI was an inch lower than before and I never touch the elevation since I have zeroed it.  So I adjusted the elevation to raise the POI, and nothing would change.  I continued to turn it until the I have reach the max.  POI still remained low.  So the inner tube is not moving up when I am making the adjustments.  I turned it down to check and POI would go down with the adjustment.  The scope just wouldn't go up to where it was for my zeroed range of 13yards.

Oh....so frustrated.  And this was a new replacement scope that I got from AGS.  The first one couldn't even hold zeros.  Are the Hawke scopes really bad?  I have such high hopes with this brand and all the reviews that I have read support their reputation.

I am having a second thought now.  Anyway, I had to email AGS and explained what I found with this new scope.  I am hoping that they would just help me resolve this issue without too much resistance to replace.  I have asked to exchange and pay for the extra for a Varmint.  Hopefully 3 times is a charm.

man...this AG thing is so stressful or may be just me running into bad luck this new year.

Just so you know.  I spoke to Hawke direct about a year ago and asked if their scopes are "Springer rated" and they said undeniably yes and will stand behind them!  Call them if you have not to get replaced.

[mtsheron70]

Hey Max. I have a bunch of Hawke scopes and love them!!
I had a problem or 2 and called Mike at Hawke. You pay shipping to them, cost me about $8, and they'll send you a new one no questions asked. Usually takes a few days. Great deal!!
Mike (877) 429-5347.

Joe is right!  They will stand behind these for sure.  That is why I use them from that day on!  I like Leapers but Hawke is much better in my book.  I still have Leapers and they are fine and have performed well.  But from here on out it is Hawke for me.

[HWNut]

Just as I said earlier to you almost 1000fps with JSB pellets is way too much for the HW97. From the factory they are around 18-20 Joules in .177 and up to 22 Joules in .22 but yours did 25 Joules. Now you are in the 800fps range with your HW97 which is perfectly fine!

Bet you have a sweet shooter now. Weihrauch rifles get smooth after thousands of shots and through use. Don't need to be tuned that will does the use for you. The age as a good wine.

[max115]

thanks Joe and Mts. nice to know that Hawke would stand behind their product.

I have email AGS and waiting for their reply.

Hope things will go my favor very quickly.

thanks guys.

[max115]

AGS will replace my Hawke and upgrade to the Varmint.   

[HWNut]

AGS will replace my Hawke and upgrade to the Varmint.   

Yeah, read it already on the WeihrauchOwners Forum. Good for you!

What are you getting now? 4-12 or the 6-24 x 44mm?

I would go with the 4-12. It's plenty of zoom for air rifle ranges.