Bare shafting Montana...Help Please

[Hilton1240]

Hello everyone,

I hope you can help. I have read so many other posts trying to figure this, but can't figure out where to go from here. I am bare shafting my 55lb Montana longbow with a 28in or just under draw with skinny FF string for the first time. I am using ICS carbon arrows spine 340. 175g head with 100g brass insert.
Results so far: Started with full length shaft had heavy nock left until cut to 30.5in I get little (2in) nock left at 10yds. I heard this doesn't matter as much with higher foc arrows (this one 22-23%) so I am using a midline down the target as well. At 20-35yds i am hitting just right of the line with a little nock Right.
Using 2 shafts I cut one to 30.25 and it looks straighter  at 10yrds, but tends to cross the line at ditance. I
Like I said this is my first time doing this and am trying to do it right, but may not be. I
 Getting a little frustrated, but my shot consistency is getting better.
Any suggestions would be appreciated.
Thank you,
Hilton1240

[the rifleman]

When you say your shot consistency is getting better it sounds like that you are making progress in this aspect.  My advice would be to continue to work on form and just enjoy shooting.  It sounds like your arrows should be close enough for now.  Shoot for a few weeks or months and shoot bareshafts every now and then to verify results.  I have tuned arrows in the past only to find that I had serious form issues.  Once these were addressed I found my arrows to be too weak.  It sounds like you are on the right path.  Take your time and enjoy.  Once you have your form down, bareshafting results will be more meaningful and you can move out to 20 yards, even 30 to micro tune.

[JR Williams]

If you are only a few inches right of the line out to 35 I would say you are there. I would fletch up a few at that length and see how they shoot. If the look good with field tips put a Broadhead on and see if the impact with field tips.

I bareshaft and a few inches right of centerline and a touch nock high is what I am after. The fletching will add a bit of stiffness to your arrows.

[moebow]

I'm with rifleman on this.  And will take it a step farther.  Unless you have your shot execution and release absolutely mastered, the only thing bare shafting will tell you or show you is your execution proficiency.  

Not sure why you want to shoot 275 grains up front when 125 is the starting point weight for starting out. (Yes! I'm aware of and have read the Ashby report!) AND, I understand that you MAY need 340 spine with that "anvil" for a point. Also not sure what your experience is but still suggest that bare shafting shows shot execution proficiency long before it shows proper spine.

Arne

[Hilton1240]

Thank you for the comments and help I will fetch some at that length and see. I was just concerned with the different nock left close and nock right at distance.
I am using the 275g up front to get the weight and to experiment with the benefits the higher FOC may hold.
The arrows will be for hunting.
I know your right about shot execution. I did learn mine needs work by doing this. Over the week it has gotten better. To be honest my experience is low. I have shot a bow for many years, but all self-taught after finding one at my father's house years ago. Different story.
I still have a lot to learn, but I enjoy working on it.
Thank you and I will post the results.

[M60gunner]

Like was said, pay attention to your form. Heavy arrows hide lots of things.

[Orion]

How is the Montana side plate cut?  Is it proud of center?  Even with 275 grains up front, I think a .340 shaft is way too heavy for a slightly less than 55# mild r/d longbow.

Using Easton's way of measuring spine (which is the standard for aluminum and carbon nowadays) a 1.94# weight suspended between two posts 28 inches apart, a .340 deflection is a spine of 92-93#.  A .400 spine might work for you, and, if the Montana is cut 1/8-inch proud of center,  I wouldn't be surprised if a .500 spine would do it. (Yes, even with 275 grains up front and the arrow cut to about 29 inches BOP, an inch longer than your draw length.)

[JRY309]

In my opinion a 340 spine carbon is too stiff for a 55# longbow with an offset riser no matter howmuch weight is up front.You may be getting false reading because carbons recover much quicker then  other arrows.How long is your draw length?I have run across the same thing trying to tune a too stiff of a carbon arrow to a bow with an offset riser.I know the theory is add weight to weaken the spine but that does not always work on bows with an offset riser.The arrow maybe bouncing off the riser instead of flexing around it.My opinion is too stiff an arrow,you may never get consistent arrow flight that you want.Working on your form is good,but you maybe fighting yourself with too stiff of a carbon arrow?My bows that I shoot a 340 spine carbon are in the 65# to 70# range.

[Zmonster]

a .500 spine would do it. (Yes, even with 275 grains up front and the arrow cut to about 29 inches BOP, an inch longer than your draw length.)
 

This

[Hilton1240]

Thanks for all the responses. I will have to try the other spines. Originally I was going off the spine selector on 3rivers for the 340s. I was worried The 400s would have to be to short.
The bow is said to be center cut and I have a very thin shaved down Velcro plate. It has been raining here for a week so I have made little progress. I
have a couple old 400 spine carbons and some 2016s I will play around with those. Let you know how it goes.
Thank you

[Twostrings2]

Would I be correct in assuming that mention of hitting or missing the target is frowned upon in tuning threads?

[Friend]

If your 175 BH on a fletched shaft shares the same mark as your 175 gn fletched field tipped shaft out to 35 yards, you are golden no matter the bareshaft results.

[Possum Head]

I would lean to 400s as I've shot them full length from slightly heavier bows with exactly the same weight up front with great flight results.

[Hilton1240]

Sorry this has taken some time. It rained for several more days and with kids and work daylight hours are few. I fletched up the 340s and some 400s. The 400s are 29.5 for the moment. I don't know if it's the weight or what but the 340s at 30.5 seem to fly better. I am waiting on some more feathers to come in to do broadhead tresting.
I did do a paper tune in the 340s and got bullet holes with that. Also the bare shafts group with the fletched. I know it seems weird.
Twostrings2 i am not missing the target i have a line down the middle of the target i was referring to as hitting just right of the line.
I am going to keep at it. Let you know how it goes.

[JR Williams]

It’s not wierd if they fly straight! I used to shoot a MOAB cut shy of center, 55. @28 and I draw 28.5 in. With 315 grain heads on 340 shafts I was still slightly weak when I cut down the shaft as far as I was comfortable. It wasn’t a false weak as when I dropped tip weight the arrows showed stiff.

There are so many variables, release, grip, strings and silencers, center cut and strike place thickness, nock fit etc etc, that affects arrow spine and flight.

So if your  bare shafts fly straight, you are showing bullet holes through paper, and your Broadhead hits with your fieldpoints....... that is tuned!

[Hilton1240]

Well I put my broadheads on tonight. All shafts are grouping out to 20 yards, fletched, broadheads, and bare. Had to put it up before I got out to 30. Thanks I will shoot these for a while until I get tight groupings to 25 and 30 and then reevaluate like you guys said. I just moved my backstop to give me the 20-35 yard distances, before tuning. Thank you for your comments and help.

[JR Williams]

Sounds like it all worked out.